300–309

Millennium: 1st millennium
Centuries: 3rd century – 4th century – 5th century
Decades: 270s 280s 290s – 300s – 310s 320s 330s
Years: 300 301 302 303 304 305 306 307 308 309
Categories: Births – Deaths – Architecture
Establishments – Disestablishments

The 300s decade ran from January 1, 300, to December 31, 309. It was the first decade of the 4th century.

Contents

Roman Empire

This decade was marked by the rule of the Tetrarchy in the Roman Empire. The Tetrarchy was a merit system instituted by Diocletian in 285 that envised the joint rule of two Augusti and two Caesars (the Caesars ranking under the Augusti), each of the emperors focusing in a certain area of the Empire. This is a compendium of the Roman Emperors that ruled during this decade:

A chart of the diarchy and tetrarchy from 285 to 305.
A chart of the tetrarchy from 305 to 306, after the retirement of Diocletian and his colleague Maximian, and the accession of Constantius and Galerius.
A chart of the tetrarchy from 306 to 307. After the usurper Maxentius declared himself Caesar, Augustus Severus marched on Rome but was defeated when his troops deferred to Maxentius. Severus was later executed in the same year, 307. Maxentius, and his father and former Augustus, Maximianus (Maximian), declared themselves AVGVSTI later that year.
Maximianus joined the secessionist regime of his son, Maxentius, in Italy. Constantine joined the secessionist alliance by marrying Maximianus' daughter, Fausta, and by supporting Maxentius in Italy. However, Constantine remained neutral with Galerius, but he still took the title of AVGVSTVS in the secessionist regime.

285–305

Augusti
East Diocletian (285 305)
West Maximian (285–305)
Caesars
East Galerius (293–305)
West Constantius Chlorus (293–305)
Augustus
Britania Carausius (286–293)
Allectus (293–296)
Usurpers
Amandus et Aelianus – leaders of the Bagaudae in Gaule (285–286)
Sabinus Iulianus – Africa Zeugitana (circa 285–293)
Domitius Domitianus – Aegyptus (296–297)
Aurelius Achilleus – Aegyptus (297–298)
Eugenius – Syria Coele (303/304)

305–306

Augusti
East Galerius (305–306)
West Constantius Chlorus (305–306)
Caesars
East Maximinus Daia (305–306)
West Severus (305–306)

306–307

Augusti
East Galerius (306–307)
West Severus (306–307)
Caesars
East Maximinus Daia (306–307)
WestConstantine I (306–307)
Caesars
West Maxentius (307)

307–313

Augusti
Illyricum Galerius (307–311)
Gallia, Hispaniae et Britannia Constantine I (307–...)
Trhacia et Pontus Licinius (308–...)
Italia Maxentius (307–312)
Oriens from Taurus to Aegyptus Maximinus Daia (310–313)
Italia Maximian (307–310)
Caesars
Oriens from Taurus to Aegyptus Maximinus Daia (307–310)
Usurpers
Domitius Alexander – Africa (308–311) Constantine's Allied

Persian Empire

East Asia

In Yamato (Japan), the Kofun period doinated during this decade. It was an animistic culture which existed prior the introduction of Buddhism. A legend of the 4th century Prince Yamato Takeru alludes to the borders of the Yamato and battlegrounds in the area. A frontier was obviously somewhere close to the later Izumo province (the eastern part of today's Shimane prefecture). Another frontier, in Kyūshū, was apparently somewhere north of today's Kumamoto prefecture. The legend specifically states that there was an eastern land in Honshū "whose people disobeyed the imperial court", against whom Yamato Takeru was sent to fight. That rivalling country may have been located rather close to the Yamato nucleus area itself, or relatively far away. The today Kai province is mentioned as one of the locations where prince Yamato Takeru sojourned in his said military expedition.

Northern frontier of this age was also explained in Kojiki as the legend of Shido Shogun's (四道将軍: Shoguns to four ways) expedition. Out of four shoguns, Ōbiko set northward to Koshi and his son Take Nunakawawake set to eastern states. The father moved east from northern Koshi while the son moved north on his way, and they finally met at Aizu (current western Fukushima). Although the legend itself is not likely to be a historical fact, Aizu is rather close to southern Tōhoku, where the north end of keyhole kofun culture as of late 4th century is located.

Mesoamerica

Unorganized tribes