Byzantine navy

The Byzantine navy comprised the naval forces of the Byzantine Empire. Like the empire it served, it developed directly from its earlier imperial Roman counterpart, but in comparison with its precursor played a far greater role in the defense and survival of the state. While the fleets of the Roman Empire faced few great naval threats, operating as a policing force and vastly inferior in power and prestige to the legions, the sea was vital to the very existence of Byzantium, which several historians have called a "maritime empire".^[3] Throughout its history, the Empire had to defend a long coastline, often with little hinterland. In addition, shipping by sea was always the quickest and cheapest way of transport, and the Empire's major urban and commercial centers, as well as its most fertile areas, lay close to the sea.^[4] Nevertheless, the nature and limitations of the maritime technology of the age meant that the Byzantines could not develop a true thalassocracy. Combined with the traditional predominance of the great Anatolian land-holders in the higher military and civil offices, this meant that the navy, even at its height, was still regarded largely as an adjunct to the land forces, a fact clearly illustrated by the relatively lowly positions its admirals held in the imperial hierarchy.^[5]

With the Muslim conquests from the 7th century onwards, the Mediterranean Sea ceased being a "Roman lake" and became a battleground between Byzantines and Arabs. Not only were the Byzantine fleets critical in the defense of the Empire's far-flung possessions around the Mediterranean basin, but they also played a major role in the defense of the imperial capital of Constantinople from seaborne attacks. Through the use of "Greek fire", the Byzantine navy's best-known and feared secret weapon, Constantinople was saved from several sieges and numerous naval engagements were won for the Byzantines. Thus, by the early 9th century, the Byzantine navy, a well-organized and maintained force, was again the dominant maritime power in the Mediterranean. The antagonism with the Muslim navies continued until the 11th century, during which the navy, like the Empire itself, began to decline.

From that point on, the Byzantines were forced more and more to rely on the navies of allied Italian city-states like Venice and Genoa, with disastrous effects on their economy and sovereignty. A brief recovery under the Komnenians was followed by another decline. Several emperors of the Palaiologan dynasty tried to revive the navy, but their efforts had only a temporary effect. By the mid-14th century, the Byzantine fleet, which once could field hundreds of warships, was limited to a few dozen at best.^[6] The diminished navy drifted on and continued to be active until the fall of the Byzantine Empire to the Ottomans in 1453.

History

Early period

4th – 5th centuries

The Byzantine navy, like the East Roman or Byzantine Empire itself, was a continuation of the Roman Empire and its institutions. After the Battle of Actium in 31 BC, and in the absence of any external threat, the Roman navy in the Mediterranean performed mostly policing and escort duties. The Roman fleets were therefore composed of relatively small vessels, best suited to these tasks. Massive sea battles, like those fought in the Punic Wars, no longer occurred. By the early 4th century, the permanent Roman fleets had dwindled, so that when the fleets of the rival emperors Constantine the Great and Licinius clashed in 324 AD,^[7] they were composed to a great extent of commandeered ships from the port cities of the Eastern Mediterranean.^[8] From this time until the early 6th century, fleets would be gathered on an ad hoc basis.^[9]

By the late 5th century, the Western Mediterranean had fallen in the hands of barbarian kingdoms. The conquests of Justinian I restored Roman control over the entire sea, which would last until the Muslim conquests in the latter half of the 7th century.

From the 420s onward, Rome's naval hegemony in the Mediterranean was challenged by the powerful navy of the Vandalic Kingdom of Carthage. Under the capable king Geiseric, the Vandals carried out devastating raids against the coasts of Italy and Greece. The Western Empire was impotent, its navy having dwindled to almost nothing,^[10] but the eastern emperors could still call upon the resources and naval expertise of the Eastern Mediterranean. A huge expedition was assembled under Basiliscus against the Vandals in 468, reputedly numbering 1,113 ships and 100,000 men, but it failed disastrously. About 600 ships were lost, and the financial cost of 130,000 pounds of gold and 700 pounds of silver nearly bankrupted the Empire.^[11] This forced the Empire to come to terms with Geiseric, signing a peace treaty. After Geiseric's death in 477 however, the Vandal threat receded.

6th century

In 513, the magister militum per Thracias, Vitalian, revolted against Emperor Anastasius I. The rebels assembled a fleet of some 200 ships, but after a few successes, they were destroyed by admiral Marinus, who employed an incendiary substance (possibly an early form of Greek fire) to defeat them.^[9] In 533, an army of 15,000 under Belisarius was transported to Africa by an invasion fleet of 92 dromons and 500 transports (the entire fleet was manned by 30,000 men),^[12] beginning the Vandalic War, the first of Justinian's Wars of Reconquest. These were largely made possible by the control of the Mediterranean waterways, and the fleet played a vital role in carrying supplies and reinforcements to the widely dispersed Byzantine expeditionary forces and garrisons. This fact was not lost on the Byzantines' enemies, and the Ostrogoth king Totila created a fleet of 400 warships with which to deny the seas around Italy, then in the throes of the Gothic War, to the Empire. In 545, General Belisarius personally commanded 200 ships against the Gothic fleet that blockaded the mouths of the Tiber, in order to save Rome.^[13] In 550 Totila invaded Sicily, and in the next year, his fleet captured Sardinia and Corsica, and raided Corfu and the coast of Epirus. However, a defeat at Sena Gallica marked the beginning of the final Imperial ascendancy.^[9] With the final conquest of Italy and southern Spain under Justinian, the Mediterranean once again became a Roman lake.^[9]

The only major naval action of the next 80 years was during the Siege of Constantinople by the Sassanid Persians and Avars/Slavs in 626. The Slavs' fleet of monoxyla was intercepted by the Byzantine fleet and destroyed, denying the Persian army passage across the Bosporus and eventually forcing the Avars to retreat.^[14]

The struggle against the Arabs

The emergence of the Arab naval threat

During the 640s, the Muslim conquest of Syria and Egypt created a new threat, as the Arabs not only conquered significant recruiting and revenue-producing areas, but, after the utility of a strong navy was demonstrated by the short-lived Byzantine recapture of Alexandria in 644, they took to creating a navy of their own. In this effort, the Arabs used the manpower of the conquered Levant, which until a few years ago had provided ships and crews for the Byzantines.^[15] As a result, and because of a shared Mediterranean maritime tradition and mutual interactions in the subsequent centuries, the Arab ships were very similar to their Byzantine counterparts.^[16] This similarity also extended to tactics and general fleet organization, with translations of Byzantine military manuals being available to the Arab admirals.^[17]

After seizing Cyprus in 651, the young Arab navy decisively defeated the Byzantines under the personal command of Emperor Constans II in the Battle of the Masts of 655, destroying 500 Byzantine ships, and began a centuries-long series of naval conflicts over the control of the Mediterranean waterways.^[18] During this period, the Byzantine fleet proved instrumental to the survival of the Empire: through the use of its newly-developed feared secret weapon, the "Greek fire", the first Arab Siege of Constantinople ended in failure when the Byzantines defeated the Arab navy, saving the Empire and halting the Muslim advance. In the 680s, under Justinian II, great care was shown to the navy, which was strengthened by the resettlement of over 18,500 Mardaites in the Empire, where they were employed as marines and rowers.^[19]

Nevertheless, the Arab naval threat intensified as they gradually took control of North Africa.^[20] The last Byzantine stronghold, Carthage, fell in 698, although a Byzantine naval expedition managed to briefly retake it. The loss of Africa meant that soon, Byzantine control of the western Mediterranean was challenged by a new Arab fleet operating from Tunisia.^[21]

The Byzantine counter-offensive

Emperor Leo III the Isaurian and his son and successor, Constantine V. Together, they spearheaded a revival of Byzantine fortunes against the Arabs, but also caused great internal strife because of their iconoclastic policies.

In 718, the second and last Arab siege of Constantinople failed, again due to the use of Greek fire, which caused great losses and fear to the besiegers. In its aftermath, the retreating Arab fleet was decimated in a storm, and Byzantine forces launched a counteroffensive, with a fleet sacking Laodicea and an army driving the Arabs from Asia Minor.^[22][23] For the next half-century, naval warfare featured constant raids from both sides. In 727, a revolt of the thematic fleets, largely motivated by resentment against the Emperor's iconoclasm, was put down by the imperial fleet through use of Greek fire.^[24] Despite the losses this entailed, twenty years later, aided for the first time by ships from the Italian city-states, the Byzantines decisively defeated the combined Syrian and Alexandrian fleets, breaking the naval power of the Umayyad Caliphate. Together with the collapse of the Ummayyad state shortly thereafter, this victory ushered the second period of complete Byzantine naval superiority in the Mediterranean.^[15] The resurgent Byzantine navy inspired respect and fear in its opponents: to stand watch on the coasts of Syria, guarding against a raid by the Byzantine fleet, was deemed by the Muslims more pious an act than a night of prayer in the Kaaba.^[25] This supremacy was further ensured by the destruction of the North African flotillas, and coupled with severe trading limitations imposed on Muslim traders, which, given the Empire's ability to control the waterways, strangled Muslim maritime trade.^[20]

These successes enabled Emperor Constantine V to shift the fleet from the Mediterranean to the Black Sea during his campaigns against the Bulgars in the 760s. In 763, a fleet of 800 ships carrying 9,600 cavalry and some infantry sailed to Anchialus, where he scored a significant victory, but in 766, a second fleet, allegedly of 2,600 ships, again bound for Anchialus, sank en route.^[26]

Renewed Muslim ascendancy

"During that time [...] the Muslims gained control over the whole Mediterranean. Their power and domination over it was vast. The Christian nations could do nothing against the Muslim fleets, anywhere in the Mediterranean. All the time, the Muslims rode its wave for conquest."

Ibn Khaldun, Muqaddimah, III.32[27]

The Byzantine naval dominance of the Mediterranean was to last until the 820s, when a succession of disasters spelled its end. The first disaster was the revolt of Thomas the Slav in 821, which carried along a large part of the Byzantine armed forces including the thematic fleets. Despite its suppression, it severely depleted the Empire's defenses. As a result, Crete fell in 824 and became a base for Muslim piratical activity in the Aegean, while under the new Abbassid Caliphate, Arab naval power was revived, and a series of reverses were inflicted on the Empire in the West.^[28] There, in 827, the Aghlabid dynasty began the slow conquest of Sicily, which was critically aided by the defection of the Byzantine commander Euphemius, together with the island's thematic fleet.^[28] By the 840s, Arabs were raiding Italy and the Adriatic. Two large-scale Byzantine attempts to reconquer Sicily were heavily defeated in 840 and 859, and the Muslim fleets, together with large numbers of independent ghazi raiders, emerged as the major power of the Mediterranean, putting the Byzantines and the Christians in general on the defensive.^[28][29] In the East, despite some successes, such as the razing of Damietta by a Byzantine fleet of 85 ships in 853, the Byzantines were constantly engaged in many operations around the Aegean and off the Syrian coast with at least three more fleets, numbering 300 ships in total.^[30]

The same period, when a battered Byzantium defended itself against enemies on all fronts, also saw the emergence of a new threat from an unforeseen direction: the Rus' made their first appearance in Byzantine history with a raid against Paphlagonia in the 830s, followed by a major expedition in 860.^[31] Due to the absence of the fleet from the Black Sea, these raids went largely unhindered.

The "Byzantine Reconquest"

For more details on this topic, see Byzantium under the Macedonians.

During the course of the latter 9th and the 10th century, as the Caliphate fractured into smaller states and Arab power became weakened, the Byzantines launched a series of successful campaigns against them. This "Byzantine Reconquest" was overseen by the able sovereigns of the Macedonian dynasty (867–1056), and marked the high water-mark of the Byzantine state.

The reign of Basil I

Gold solidus of Emperor Basil I the Macedonian. His patronage of the fleet resulted in several successes and was long remembered by the sailors, forming strong ties of loyalty to the Macedonian dynasty that were felt up until the days of his grandson, Constantine VII.^[32]

The ascension of Emperor Basil I heralded this revival, as he embarked on an aggressive foreign policy. Continuing the policies of his predecessor, Michael III, he showed great care to the fleet, and as a result, successive victories followed: in 867, a fleet under the droungarios tou plōïmou Niketas Ooryphas relieved Dalmatia from Arab attacks and reestablished Byzantine presence in the area,^[33] while a few years later, he twice heavily defeated the Cretan pirates,^[34] temporarily securing the Aegean.^[28] At the same time Cyprus was temporarily recovered and Bari occupied.^[35] In 878 however, Syracuse, the main Byzantine stronghold in Sicily, was lost, largely because the Imperial Fleet was occupied with transporting marble for the construction of the Nea Ekklesia, Basil's new church.^[36] Ooryphas' successor, the droungarios Nasar, scored a significant victory over the Tunisians who were raiding the Ionian Islands in 880, and proceeded to raid Sicily, carrying off much booty.^[37] While a short-lived Byzantine counter-offensive in the 880s, under Nikephoros Phokas the Elder, managed to expand its foothold in Apulia and Calabria, which would later evolve into the Catepanate of Italy, a heavy defeat off Milazzo in 888 signaled the virtual disappearance of significant Byzantine naval activity from Italy for the next century.^[28]

Arab raids during the reign of Leo VI

Despite the successes under Basil, during the reign of his successor Leo VI the Wise, the Arab naval threat reached new heights, as successive raids devastated the shores of Byzantium's naval heartland, the Aegean Sea. In 891–893, the Arab fleet sacked the island of Samos and took its stratēgos prisoner; in 898, the eunuch admiral Raghib carried off 3,000 Byzantine sailors as prisoners; and in 901, the renegade Damian of Tyre plundered Demetrias.^[38] In 902, the Empire lost Taormina, its last outpost in Sicily, and in July 904, another renegade, Leo of Tripoli, sacked the Empire's second city, Thessalonica, while the Empire's fleet remained passive in the face of the Arabs' superior numbers.^[39] The defensive Byzantine mindset of the time is clearly evident in the tactics advocated in Leo's Naumachica.^[28] Early in Leo's reign, in 895, a part of the Imperial Fleet was also involved in the war against Bulgarian Tsar Simeon, ferrying an army of Magyars across the Danube to raid Bulgaria.^[40]

The most distinguished Byzantine admiral of the period was Himerios, the logothetēs tou dromou. Appointed admiral in 904, he was unable to prevent the sack of Thessalonica, but he scored a first victory in 906, and in 910, he led a successful attack on Laodicea.^[41] The city was sacked and its hinterland plundered and ravaged without the loss of any ships.^[42] A year later, however, a huge expedition under Himerios against the Emirate of Crete, comprising a fleet of 112 dromons and 75 pamphyloi with 43,000 men, failed,^[43] followed by a catastrophic defeat at the hands of Leo of Tripoli off Samos, as the fleet returned to Constantinople.

The year 920 witnessed the ascension of an admiral, Romanus Lecapenus, to the Imperial throne, for the second (after Tiberius Apsimarus) and last time in the Empire's history. Finally, in 921 or 924, the decisive defeat of Leo of Tripoli off Lemnos marked the beginning of the Byzantine resurgence.^[44]

The recovery of Crete and the Levant

In 961, Nikephoros Phokas led a huge amphibious operation which recovered Crete for the Empire, thus securing the safety of the Aegean Sea from the Muslim pirate threat.

In 949, an expedition of about 100 Byzantine ships (20 dromons, 64 chelandia, and 10 galeai) carrying 4,100 men against the Emirate of Crete failed,^[45] but in 960, Nikephoros Phokas set out with a fleet of 100 dromons, 200 chelandia, and 308 transports carrying, together with their crews, a force of 77,000 men to subdue the island.^[46] The conquest of Crete removed the direct threat to the Aegean, Byzantium's naval heartland, while the conquest of Cilicia, Cyprus (in 968),^[47] and the northern Syrian coast removed the threat of the once mighty Muslim Syrian fleets, effectively re-establishing Byzantine dominance in the Eastern Mediterranean.^[44]

In the Black Sea, a hastily assembled fleet of 15 old ships equipped with Greek fire managed to defeat a new Rus' fleet that was threatening Constantinople in 941, and the navy played an important role in the Rus'–Byzantine War of 968–971, when John I Tzimiskes sent 300 ships to blockade the Kievan Rus from the Danube.^[48] In the West, however, a heavy Byzantine defeat by the Fatimids at the Straits of Messina in 965 resulted in the end of significant naval activity until after 1025, when Byzantium again actively intervened in southern Italy and Sicily. Nevertheless, during the 11th century, both the Byzantine and Muslim navies gradually declined, a phenomenon parallel to the rise of the naval power of the Italian city-states.^[44]

Komnenian period

For more details on this topic, see Byzantium under the Komnenoi.

By the end of the 11th century, the Byzantine navy was a shadow of its former self, having declined through neglect, the incompetence of its officers, and lack of funds.^[49] Kekaumenos, writing in ca. 1078, laments that "on the pretext of reasonable patrols, [the Byzantine ships] are doing nothing else but ferrying wheat, barley, pulse, cheese, wine, meat, olive oil, a great deal of money, and anything else" from the islands and coasts of the Aegean, while they "flee [the enemy] before they have even caught sight of them, and thus become an embarrassment to the Romans."^[50] By that time, the Muslim naval threat had vanished, but a new and powerful adversary had risen: the Norman Kingdom of Sicily, which had designs on the Byzantine Adriatic coasts and beyond. The sorry state of the Byzantine fleet had dire consequences, as the Norman invasion could not be forestalled, leading to a decade of war, which consumed the scant resources of the embattled Empire.^[51] Furthermore, Emperor Alexios I Komnenos (1081–1118) was forced to call upon the assistance of the Venetian fleet against the Normans. In exchange for their help, in 1082, he granted them major trading concessions. This, and subsequent extensions of these privileges, practically rendered the Byzantines hostage to the Venetians: "Byzantium's lack of a navy [...] meant that Venice could regularly extort economic privileges, determine whether invaders [...] entered the Empire, and parry any Byzantine attempts to restrict Venetian commercial or naval activity."^[51]

Alexios inevitably realized the importance of having his own fleet, and despite his preoccupation with land operations, he took steps to re-establish the navy's strength. His efforts bore some success, especially in countering the attempts by Turkish emirs like Tzachas of Smyrna to launch fleets in the Aegean.^[52] With the aid of the Crusaders, Alexios was able to regain the coasts of Western Anatolia and expand his influence eastwards: in 1104, a Byzantine fleet of 10 ships captured Laodicea and other coastal towns as far as Tripoli.^[53] By 1118 Alexios was able to pass on a modest navy to his successor, John II Komnenos (1118–1143). Like his father, John II concentrated on the army and regular land-based campaigns, but he took care to maintain the navy's strength and provisioning system.^[54] This did not avert an embarrassment when John refused to renew the trading privileges that Alexios had granted to the Venetians; after they had plundered several Byzantine islands in retaliation, John was forced to renew the treaty. Evidently the Byzantine navy at this point was not sufficiently powerful for John to successfully confront Venice, especially as there were other pressing demands on the Empire's resources. Not long after this incident however, John II cut funding to the fleet and transferred it to the Byzantine army.^[55]

The naval expeditions of Manuel I

The navy enjoyed a major comeback after 1143 under the ambitious emperor Manuel I Komnenos (1143–1180), who used it extensively as a powerful tool of foreign policy in his relations with the Latin and Muslim states of the Eastern Mediterranean.^[56] In 1148, Manuel personally commanded an army of 20–30,000 men along with a fleet of 500 galleys and 1,000 transports that succeeded in recapturing Corfu and the Ionian Islands from the Norman Kingdom of Sicily,^[57] and in 1155, a Byzantine fleet of 10 ships in support of Norman rebel Robert III of Loritello landed at Ancona, launching the last Byzantine bid to regain Southern Italy. Despite initial successes, the expedition was ultimately defeated in 1156, and 4 Byzantine ships were captured.^[58] In 1169, a large fleet of about 20 large warships, 150 galleys, and 60 horse transports under megas doux Andronikos Kontostephanos was sent to invade Egypt in cooperation with the ruler of the Crusader Kingdom of Jerusalem.^[59] The twenty huge vessels were used to carry arms, and engines and machines of war. The one hundred and fifty ships of war were equipped with beaks, while the sixty larger boats carried horses.^[59] Historian William of Tyre was impressed by the spectacle it provided, noting the swift dromons and the large horse transports used by the navy to transport the Byzantine cavalry. The invasion failed and the Byzantines lost half (about 100 ships) in a storm on the way back.^[60] In 1171, Kontostephanos with 150 ships chased off a Venetian fleet away from Chios,^[61] and in 1177, another fleet of 150 ships under Kontostephanos, destined for Egypt, returned home after appearing off Acre due to the refusal of Count Philip of Flanders and many important nobles of the Kingdom of Jerusalem to help.^[62] However, by the end of Manuel's reign, the strains of constant warfare on all fronts and the Emperor's various grandiose projects had become evident: the historian Nicetas Choniates attributes the rise of piracy to the diversion of the funds, provided by the Aegean islands for the maintenance of the fleet, to cover the needs of the imperial treasury.^[63]

Decline

The Angeloi dynasty

Byzantine Culture
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For more details on this topic, see Byzantium under the Angeloi.

After the demise of the Komnenian dynasty in 1185, the navy deteriorated swiftly and hopelessly: the extent of the navy's decline was illustrated by the fact that the Byzantines came to rely on hiring pirates to fight for them.^[59] In the 1180s, expeditions of 70–100 ships are still recorded in contemporary sources,^[64] but their operations were rarely successful: in 1185, Alexios II's successor, Emperor Andronikos I, prepared 100 ships in the Sea of Marmara to prevent the Norman fleet from reaching Constantinople.^[65] In 1186, with his brother Alexios III being held captive in Acre, Emperor Isaac II Angelos sent 80 galleys to liberate him, but the fleet was destroyed off Cyprus by the Norman pirate Margaritus of Brindisi. Later in the same year, another Byzantine fleet of 70 ships was sent by Isaac II to recapture Cyprus from Isaac Komnenos, but was also defeated by Margaritus.^[66] In an attempt to regain some lost territories in the Holy Land, in 1189 the Byzantine Emperor agreed to send 100 galleys to aid Saladin in capturing Antioch.^[67]

The general decline continued, and by 1196 there were only about 30 galleys left.^[6] The emperors were driven to rely on the help of the Venetians, and later the Genoese: already in 1187 an agreement was made by Isaac II with Venice, in which the Republic would provide 40–100 galleys at six months' notice in exchange for favorable trading concessions. By the time the Fourth Crusade arrived at Constantinople in 1203, there were only 20 ships, so decayed that during the siege, 17 of those ships were used as fireships in a failed attempt against the Venetian fleet.^[6]

Nicaea and the Palaiologan period

For more details on this topic, see Byzantium under the Palaiologoi.

After the Fourth Crusade, the Nicaean Emperors initially pursued a policy of consolidation. Naval operations were limited, but in 1225, the Nicaean fleet was able to occupy the islands of Lesbos, Chios, Samos, and Icaria. Only after the recapture of Constantinople in 1261 was the Emperor Michael VIII Palaiologos able to focus his attention on the fleet. In the early 1260s, the Byzantine navy was still weak, as evidenced by the defeat of a combined Byzantine-Genoese fleet of 48 ships by a much smaller Venetian fleet in 1263.^[68] By 1270 however, Michael's efforts produced a strong navy of 80 ships, with several Latin privateers sailing under imperial colors. In the same year, a fleet of 24 galleys besieged the town of Oreos in Negroponte (Euboea), and defeated a Latin fleet of 20 galleys.^[69] This marked the first successful independent Byzantine naval operation and the beginning of an organized naval campaign in the Aegean, that would continue throughout the 1270s and would result in the recapture, albeit briefly, of many islands from the Latins.^[70]

This revival did not last long. Michael's successor Andronikos II Palaiologos (1282–1328) wrongly assumed that by relying on the naval strength of his Genoese allies he could completely do without the maintenance of a fleet, with its particularly heavy expenditure. He therefore disbanded the navy, and instead hired 50–60 Genoese galleys in 1291. Andronikos' cutbacks of military expenditures had severe effects: during his long reign, the Turks gradually took permanent possession of the Aegean coasts of Anatolia, with the Empire unable to reverse the situation. In ca. 1320, the Emperor belatedly tried to rebuild the navy by constructing 20 ships, but this effort came to naught.^[6] His grandson and heir Andronikos III Palaiologos (1328–1341) actively tried to rebuild the navy's strength, personally leading it in expeditions against Latin holdings in the Aegean, but his policies failed to stem the overall decline. After his reign, the highest number of warships ever mentioned to be in the Byzantine navy rarely exceeded ten, but with impressment of merchant vessels, the Byzantine navy could still occasionally increase to about 100–200 ships.^[6] The navy was very active during the Civil War of 1341–1347, in which its commander, the megas doux Alexios Apokaukos, played a prominent role.

Following the civil war, Emperor John VI Kantakouzenos tried to restore the navy and merchant fleet, as a means of both reducing the Empire's dependency on the Genoese colony of Galata, and of securing the control of the Dardanelles against passage by the Turks. To that end, he enlisted the aid of the Venetians, but in March 1349, his newly-built fleet of 9 fair-sized and about 100 smaller ships was caught in a storm off the southern shore of Constantinople. The inexperienced crews panicked, and the ships were either sunk or captured by the Genoese.^[71] In 1351, Kantakouzenos participated with only 12 ships in the war of Venice and Aragon against Genoa, but was soon forced to sign an unfavorable peace.^[72]

Kantakouzenos was the last emperor who had the means to try and restore the navy. Forty years later, during the brief usurpation of John VII, Manuel II was able to gather only 5 galleys and 4 smaller vessels (including some from the Knights of Rhodes) to recapture Constantinople and rescue his father John V.^[73] In 1396, Manuel armed 10 ships to assist the Crusade of Nicopolis, and he later personally commanded 4 galleys and 2 other vessels carrying some infantry and cavalry, and saved the island of Thasos from an invasion.^[74] The last appearance of the Byzantine fleet was in the final Ottoman siege of 1453, when a fleet of 10 Byzantine and 16 foreign ships defended Constantinople against the Ottoman fleet.^[75] The last naval engagement in Byzantine history took place during the siege on 20 April 1453, when 3 Genoese galleys and 1 Byzantine transport fought their way through the Ottoman blockade into Constantinople.^[76]

Organization

Early period (4th – mid-7th centuries)

Under Emperor Diocletian, the navy's strength increased from 46,000 men to 64,000 men,^[77] a figure that represents the numerical high tide of the late Roman navy. By the 4th century, the large, permanent fleets of the early Empire had been progressively broken up in smaller squadrons. During the 4th and 5th centuries, the situation regarding the structure of the navy is somewhat unclear. The Danube Fleet (Classis Histrica) is still well attested in the Notitia Dignitatum, and its increased activity is commented upon by Vegetius.^[78] In the West, several fluvial fleets are mentioned, but the old standing praetorian fleets had all but vanished,^[79] and even the remaining western provincial fleets appear to have been seriously understrength and incapable of countering any significant barbarian attack.^[80] Int he East, the Syrian and Alexandrian fleets are known from legal sources to have remained in existence in ca. 400 AD,^[81] while a fleet is known to have been stationed at Constantinople itself, perhaps created out of the remnants of the praetorian fleets.^[8] Its size however is unknown, and it does not appear in the Notitia.^[82]

During the 5th century, for operations in the Mediterranean, fleets appear to have been assembled on an ad hoc basis and then disbanded.^[9] The first permanent Byzantine fleet can be traced to the revolt of Vitalian in 513–515, when Anastasius I created a fleet to counter the rebels' own.^[9] This fleet was retained, and under Justinian I and his successors it developed again into a professional and well-maintained force.^[15] Due to the absence of any naval threat however, the fleet of the late 6th century was relatively small, with several small flotillas in the Danube and two main fleets maintained at Ravenna and Constantinople.^[83] Additional flotillas must have been stationed at the other great maritime and commercial centers of the Empire: at Alexandria, providing the escort to the annual grain fleet to Constantinople, and at Carthage, controlling the western Mediterranean.^[84] Not only did the fleet profit from the long-established naval tradition and infrastructure of those areas, but also, in the event of a naval expedition, a large fleet could be quickly and inexpensively assembled by impressing the numerous merchant vessels.^[85]

Middle period (late 7th century – 1070s)

The naval themes

The Byzantine Empire in 717. The scattered and isolated imperial possessions around the Mediterranean were defended and reinforced by the Byzantine fleets.

In response to the Arab conquests during the 7th century, the whole administrative and military system of the Empire was reformed, and the thematic system established. According to this, the Empire was divided into several themata, which were regional civil and military administrations. Under the command of a stratēgos, each thema maintained its own, locally levied forces, while on campaign they would supplement the central imperial army stationed at Constantinople. The fleet was established along similar lines, with a central Imperial Fleet (βασιλικόν πλώιμον) at Constantinople and separate provincial or thematic squadrons (θεματικοί στόλοι) provided by the maritime themes, each commanded by a droungarios (the most important were later raised to the rank of stratēgos).^[44] Unlike the earlier Roman navy, where the provincial fleets were decidedly inferior in numbers and included only lighter vessels than the central fleets, the Byzantine thematic fleets were formidable formations in their own right. The only major difference appears to have been the exclusive use of Greek fire by the Imperial Fleet.^[86]

During the course of the middle Byzantine period, the large original themes were subdivided into smaller ones, and new ones were created by conquest in the 9th and 10th centuries. Although most themes that had a shoreline maintained some ships, the naval themes (θέματα ναυτικᾶ) proper in the 8th–10th centuries were four:

• the Theme of the Carabisiani (θέμα τῶν Καραβησιάνων, "Theme of the Ships' Men", from the word κάραβις, meaning "ship"), which was the first and initially only naval theme to be established. It was created by Constans II in the 660s,^[87] possibly from the remainders of the old quaestura exercitus^[88] or the Army of the Illyricum.^[89] It was headed by a stratēgos, and included the southern coast of Asia Minor from Miletus to Seleucia in Cilicia, the Aegean islands and the imperial holdings in southern Greece. Its capital was initially at Samos, with a subordinate command under a droungarios at Cibyrra in Pamphylia. In 743, after the separation of the Theme of Hellas and a failed revolt in 727, the seat was moved to Cibyrra (and later Attaleia), being renamed into the Theme of the Cibyrrhaeots (θέμα Κιβυρραιωτῶν), under a droungarios.^[90] As it faced the Arab fleets of Egypt and Syria, it was the most important and powerful of the naval themes.^[44]
• the Theme of the Aegean (θέμα Αἰγαίου), separated from the Cibyrrhaeots in 843, included the Aegean islands except for the Dodecanese.^[91]
• the Theme of Samos (θέμα Σάμου), separated from the Theme of the Aegean Sea ca. 882.^[91] It included the Ionian coast, with capital at Smyrna.
• the Theme of Hellas (θέμα Ἑλλάδος), founded in ca. 686–689 by Justinian II, encompassing the imperial possessions of southern Greece with capital at Corinth. Justinian settled 6,500 Mardaites there, who provided oarsmen and garrisons.^[87] While not exclusively a naval theme, it maintained its own fleet. It was split in 809 into the Theme of the Peloponnese and the new Theme of Hellas, covering Central Greece and Thessaly.^[92]

Other themata with a significant naval force were:

• the Theme of Sicily (θέμα Σικελίας), responsible for Sicily and the imperial possessions in southwestern Italy (Calabria). Once the bastion of Byzantine naval strength in the West, by the late 9th century it had greatly diminished in strength, and disappeared after the final loss of Taormina in 902.^[44]
• the Theme of Ravenna, in essence the Exarchate of Ravenna, until its fall in 751.
• the Theme of Cephallonia (θέμα Κεφαλληνίας), controlling the Ionian Islands, promoted from an archontate in 809.^[92] The new imperial possessions in Apulia were added to it in the 870s, before they were made into a separate thema (that of Langobardia) in about 910.^[93]
• the Theme of Paphlagonia and the Theme of Chaldia, split off from the Armeniac Theme in ca. 819 by emperor Leo V and provided with their own naval squadrons, possibly as a defense against Rus' raids.^[94]

Manpower and size

Just as with its land counterpart, the exact size of the Byzantine navy and its units is a matter of considerable debate, due to the scantness and ambiguous nature of the primary sources. One exception are the numbers for the late 9th and early 10th century, for which we possess a more detailed breakdown, dated to the Cretan expedition of 911. These lists reveal that during the reign of Leo VI the Wise, the navy reached 34,200 oarsmen and perhaps as many as 8,000 marines.^[1] The central Imperial Fleet totaled some 19,600 oarsmen and 4,000 marines under the command of the droungarios of the basilikon plōïmon (δρουγγάριος τοῦ βασιλικοῦ πλωίμου). These four thousand marines were professional soldiers, recruited by Basil I in the 870s, and greatly strengthened the Imperial Fleet, since whereas previously the fleet had depended on thematic and tagmatic soldiers for its marines, the new force provided a more reliable, better trained and immediately available force at the Emperor's disposal.^[34] Indeed, the marines of the Imperial Fleet were considered to belong to the imperial tagmata, and organized along similar lines.^[95] The Aegean Themal Fleet numbered 2,610 oarsmen and 400 marines, the Cibyrrhaeotic Fleet stood at 5,710 oarsmen and 1,000 marines, the Samian Fleet at 3,980 oarsmen and 600 marines, and finally, the Theme of Hellas furnished 2,300 oarsmen with a portion of its 2,000 thematic soldiers doubling as marines.^[1]

The following table contains approximate estimates of the number of oarsmen over the entire history of the Byzantine navy:

Note that contrary to popular conception, galley slaves were not used as oarsmen neither by the Byzantines and the Arabs, nor by their Roman and Greek predecessors.^[101] Throughout the existence of the Empire, Byzantine crews consisted of mostly lower-class freeborn men, who were professional soldiers, legally obliged to perform military service in return for pay or land estates.^[102]

As far as ships are concerned, according to numbers provided by Constantine Porphyrogenitus, in 949 the Imperial Fleet alone mustered 100, 150 or 250 ships (the numbers depend on the interpretation of the Greek text).^[103] Accepting a number of 150, historian Warren Treadgold extrapolates a total, including the four naval themes, of ca. 240 warships, a number which was increased to 307 for the Cretan expedition of 960–961. The latter number probably represents the approximate standing strength of the entire Byzantine navy (including the smaller flotillas) in the 9th and 10th centuries.^[2]

Rank structure

Naval themes were organized much the same way as their land bound counterparts: the droungarios (and later the stratēgos) stood at the head, assisted by a deputy called topotērētēs and the prōtonotarios, who headed the civilian administration of the theme. Further staff officers were the chartoularios in charge of the fleet administration, the prōtomandatōr ("head messenger"), who acted as chief of staff, and a number of staff komētes ("counts"), including a komēs tēs hetaireias, who commanded the bodyguard of the droungarios.^[95] The major subdivisions of the theme were put under a tourmarchēs, while squadrons of ships were commanded by a komēs or droungarokomēs, and each ship's captain was called kentarchos ("centurion"), nauarchos, or, more archaically, triērarchos or kybernētēs.^[104] The marine infantry ranks followed those of the army.

Each ship's crew, depending on its size, was composed of one to three ousiai (ούσίαι, sing. ούσία) of ca. 110 men each. The rowers of the upper level were also expected to fight in a boarding action, and were therefore specially picked and equipped with light armor.^[104] Under the captain, there was the bandophoros, who acted as executive officer, two helmsmen called prōtokaraboi ("heads of the ship") and a bow officer, the prōreus.^[104] There were also a number of specialists on board, such as the two bow oarsmen and the siphōnatores, who worked the siphons used for discharging the Greek fire.^[104]

Late period (1080s – 1453)

The reforms of the Komnenoi

After the decline of the navy in the 11th century, Alexios I rebuilt it on different lines. The thematic fleets vanished, and their remnants were amalgamated into a unified imperial fleet, under the new office of the megas doux.^[54] The megas droungarios of the fleet, once the overall naval commander, was subordinated to him, acting now as his principal aide.^[105] The megas doux was also appointed as overall governor of southern Greece (the old themata of Hellas and the Peloponnese), which was divided into districts (oria) that supplied the fleet.^[106] Under John II, the Aegean islands also became responsible for the maintenance, crewing and provision of warships, and contemporary sources took pride in the fact that the great fleets of Manuel's reign were crewed by "native Romans", although use was made of mercenaries and allied squadrons.^[107]

Later, in the 13th century, another high rank, that of amiralios (ἀμιράλιος or ἀμιράλης) was introduced, being third in the hierarchy after the megas doux and the megas droungarios.^[108]

The navy of Michael VIII Palaiologos

With the decline of the Byzantine fleet in the latter 12th century, the Empire increasingly relied on the fleets of Venice and Genoa. Alongside the mistrusted Italian city-states, with whom alliances shifted regularly, mercenaries were increasingly employed in the last centuries of the Empire, often rewarded for their services with fiefs. Most of these mercenaries, like Giovanni de lo Cavo (lord of Anafi and Rhodes), Andrea Moresco (successor of de lo Cavo in Rhodes) and Benedetto Zaccaria (lord of Phocaea), were Genoese, to whom the Byzantines were often allied. Under Michael VIII, for the first time a foreigner, the Italian privateer Licario, became megas doux and was given Euboea as a fief.^[109]

At the same time, after regaining Constantinople in 1261, Michael VIII sought to lessen this dependence on foreigners and initiated a great effort to rebuild a "national" navy, forming a number of new corps to this purpose: the Gasmouloi (Γασμοῦλοι), who were men of mixed Greek-Latin descent living around the capital; and colonists from Laconia, called Lakōnes (Λάκωνες, "Laconians") or Tzakōnes (Τζάκωνες), were used as marines, forming the bulk of Byzantine naval manpower in the 1260s and 1270s.^[110] Michael also set the rowers, called Prosalentai or Prosēlontes, apart as a separate corps.^[111] All these groups received small grants of land to cultivate in exchange for their service, and were settled together in small colonies.^[112] The Prosalentai were settled near the sea throughout the northern Aegean,^[113] while the Gasmouloi and Tzakōnes were settled mostly around Constantinople and in Thrace. These corps remained extant, albeit in a diminished form, in the last centuries of the Empire (the last mention of the Prosalentai is in 1361, and of the Gasmouloi as late as 1422).^[6]

Ships

For more details on this topic, see Dromon.

The main warship of the Byzantine navy was the dromon (δρόμων). A derivation of the light liburnian galleys of the imperial Roman fleets, the term first appeared in the 6th century, during the wars of Justinian, to describe fast ships with a single row of oars. During the next few centuries, as the naval struggle with the Arabs intensified, heavier versions with two or possibly even three banks of oars evolved.^[114] Eventually, the term was used as a general reference for "warship", and in a specific sense as an alternative name for the heaviest class of warships, the chelandion.^[115]

By the 10th century, there were three main classes of two-banked ("bireme") warships: the ousiakos (οὑσιακός), so named because it was manned by an ousia of 108 men, the pamphylos (πάμφυλος), which was crewed with up to 120–160 men, and the chelandion (χελάνδιον), with a crew of up to three ousiai.^[16] The largest known crew comprised 230 rowers and 70 marines.^[116] A smaller, single-bank ship, the monērēs (μονήρης, "single-banked") or galea (γαλέα, from which the term "galley" derives), with ca. 60 men as crew, was used for scouting missions but also in the wings of the battle line.^[117] Three-banked ("trireme") dromons are described in a 9th century work dedicated to the parakoimōmenos Basil Lekapenos. However this treatise, which survives only in fragments, draws heavily upon references on the appearance and construction of a Classical trireme, and must therefore be used with care when trying to apply it to the warships of the middle Byzantine period.^[118] Nevertheless, it is possible that three-banked versions of the dromons existed.^[114]

The exact appearance and evolution of the dromon's design are a matter of debate and conjecture: until recently, no remains of a Byzantine warship had been found and information had to be gauged from literary evidence, crude artistic depictions and the remains of a few merchant vessels. In 2005–2006, archaeological digs for the Marmaray project in the location of the Harbor of Theodosius (modern Yenikapi) uncovered the remains of over 20 Byzantine ships from the 6th to 10th centuries, including galleys.^[119]

The accepted view is that dromons were generally fully decked ships, had one to two masts (histos or katartion), and used lateen sails.^[120] Each oar bank generally had about 25 oars, which extended directly from the hull (unlike ancient Greek and Hellenistic vessels, which used an outrigger),^[121] in addition to the two large steering oars in the stern. The two oar banks were divided by the deck: the rowers below deck (the zygioi) rowed from thwarts (zygoi) while those above (the thranitai) rowed from benches (thranoi) and fought alongside the marines in boarding operations.^[122]

Overall length must have been between 35 and 40 meters.^[123] The dromons had an elevated forecastle (xylokastron), through which the siphon for the discharge of Greek fire projected,^[124] although secondary siphons could also be carried amidships on either side.^[125] The larger ones had wooden castles (xylokastra) on either side between the masts, similar to those attested for the Roman liburnians, providing archers with elevated firing platforms.^[126]

For cargo transport, the Byzantines commandeered ordinary merchantmen and cargo ships (skeuophora), but there existed also a number of specialized vessels such as horse-transports (hippagōga, confusingly also called "chelandia" in some sources).^[114]

Tactics and weapons

Naval tactics

As with the land army, the Byzantines took care to codify, preserve and pass on the past lessons of sea warfare through the use of military manuals. The main surviving texts are the chapters on sea combat (peri naumachias) in the Tactica of Leo the Wise and Nikephoros Ouranos (both drawing extensively from the 6th century Naumachiai of Syrianos Magistros and other earlier works),^[118] and are complemented by relevant passages in the De administrando imperio of Constantine Porphyrogenitus and other works by Byzantine and Arab writers.^[17]

The manuals emphasized the training and welfare of the crews, the acquisition of accurate intelligence, and the maintenance of a disciplined and well-ordered formation. Advice is provided on drawing up a battle plan, but they also emphasized the need for initiative and improvisation on the part of the admiral during the actual battle. A system of transmitting orders from ship to ship through signal flags and lanterns is also prescribed.^[17] Importance is also laid on matching one's forces and tactics to the prospective enemy: Leo VI contrasts the Arabs with their heavy and slow ships, to the small and fast craft of the Slavs and Rus'.^[127]

Indeed, because medieval Mediterranean naval warfare, following the abandonment of the ram, depended on a constant barrage of missiles and boarding actions,^[128] the main task for fleet commanders was to keep their formations well ordered. Conversely, tactical maneuvers attempted to disrupt the enemy formation,^[129] including the use of various stratagems, such as dividing one's force and carrying out flanking maneuvers, feigning retreat or hiding a reserve in ambush.^[130] Indeed, Leo VI advocates the use of stratagems and advises against direct open confrontation.^[131] Fleets that failed to keep an ordered formation usually avoided battle.^[129]

According to Leo VI, a crescent formation seems to have been the norm, with the flagship in the center and the heavier ships at the horns of the formation, in order to turn the enemy's flanks.^[132] A range of variants and other tactics and counter-tactics was available, depending on the circumstance.^[17] Once the fleets were close enough, exchanges of missiles began, while the final outcome was determined by boarding actions: the ships grappled each other, and the marines, to whom the rowers of the ship's upper bank were added, engaged in hand-to-hand combat.^[133]

It must be noted that the nature of the galley navies imposed many limitations on their operational capabilities. Galleys did not handle well in rough waters and could be swamped, which would be catastrophic in the open sea. Indeed, history is replete with instances were galley fleets were sunk by bad weather.^[134] The sailing season was therefore usually restricted from mid-spring to September.^[135] The galleys' maintainable cruising speed, even when using their sails, was limited,^[136] as were the amount of supplies and water it could carry, the latter especially critical in the hot Mediterranean summers.^[137] All this meant that fleets composed of galleys were confined to coastal routes,^[134] and had to make frequent landfall to replenish their supplies and rest their crews.^[138] It is for these reasons that Nikephoros Ouranos emphasizes the need to have available "men with accurate experience of the sea [...], which winds cause it to swell and which blow from the land, and who know the hidden rocks in the sea, the places that have no depth, the land along which one sails and the islands adjacent to it, the harbours and their distance from each other."^[139]

Armament

Greek fire grenades and caltrops from Crete, dated to the 10th and 12th centuries.

Unlike the warships of Antiquity, Byzantine and Arab ships did not feature rams, and the primary means of ship-to-ship combat were boarding actions and missile fire, as well as the use of inflammable materials such as Greek fire.^[86] Despite the fearsome reputation of the latter though, it was effective only under certain circumstances, and not the decisive anti-ship weapon that the ram had been in the hands of experienced crews.^[140]

Like their Roman predecessors, Byzantine and Muslim ships were equipped with small catapults (mangana) and ballistae (toxoballistrai) that launched stones, arrows, javelins, pots of Greek fire or other incendiary liquids, caltrops (triboloi) and even containers full of asbestos or scorpions and snakes, according to some sources.^[141] Marines were heavily armored (Leo refers to them as "cataphracts") and armed with close-combat arms such as lances and swords, while the sailors fought with bows and crossbows.^[142] The importance and volume of missile fire during sea combat can be gauged from the fleet manifests for the Cretan expeditions of the 10th century, which mention 10,000 caltrops, 50 bows and 10,000 arrows, 20 hand-carried ballistrai with 200 bolts called myai ("flies") and 100 javelins per dromon.^[143] Cannons were rarely used by the Byzantines, who only had a few pieces for the defense of the land walls of Constantinople. Unlike the Venetians and Genoese, there is no indication that any were ever mounted on ships.^[144]

Greek fire

For more details on this topic, see Greek fire.

As he [the Emperor] knew that the Pisans were skilled in sea warfare and dreaded a battle with them, on the prow of each ship he had a head fixed of a lion or other land-animal, made in brass or iron with the mouth open and then gilded over, so that their mere aspect was terrifying. And the fire which was to be directed against the enemy through tubes he made to pass through the mouths of the beasts, so that it seemed as if the lions and the other similar monsters were vomiting the fire."

From the Alexiad of Anna Comnena, XI.10[145]

The term "Greek fire" was given to the concoction by the Latins (Western Europeans), as they viewed the Byzantines simply as Greeks. The native Greek name was "liquid fire" (ὑγρόν πῦρ). Although the use of incendiary chemicals by the Byzantines has been attested since the early 6th century, the actual substance known as Greek fire is believed to have been created in 673 and attributed to an engineer from Syria, named Kallinikos. The most common method of deployment was to emit the formula through a large bronze tube (siphōn) onto enemy ships.^[86] Usually the mixture would be stored in heated, pressurized barrels and projected through the tube by some sort of pump while the operators were sheltered behind large iron shields. Alternatively, it could be launched by catapults. A portable version (cheirosiphōn) also existed, reputedly invented by Leo VI, making it the direct analogue to a modern flamethrower.^[117]

The means of its production was kept a state secret, and its components are only roughly guessed or described through secondary sources like Anna Comnena, so that its exact composition remains unknown to this day. In its effect, the Greek fire must have been rather similar to napalm.^[86] Burning fiercely, it could stay ablaze even underwater for a short period. Despite the somewhat exaggerated accounts of Byzantine writers, it was by no means a "wonder weapon", and could not avert some serious defeats.^[146] Certainly, in favourable circumstances and against an unprepared enemy, its great destructive ability and psychological impact could prove decisive, as displayed against the Rus'. Greek fire was rarely used on land, the last time being the final siege of Constantinople in 1453. The Arabs eventually also fielded their own "liquid fire" after 835, but it is unknown if they used the Byzantine formula, possibly obtained through espionage or through the defection of stratēgos Euphemios in 827, or whether they independently created a version of their own.^[86]

Citations

Sources and bibliography