List of state leaders in 855

This is a list of heads of state, government leaders, and other rulers in the year 855.

Asia

• China (Tang dynasty) – Emperor Xuānzong (846–859)
• Pratihara Empire – Mihira Bhoja I (c. 836–886)
• Japan (Heian period) – Emperor Montoku (850–858)
• Korea (North South States Period)
  • Balhae – Dae Ijin (830–857)
  • Unified Silla – Munseong (839–857)

Europe

• First Bulgarian Empire – Boris I, Khan of the Bulgars (852–889)
• Byzantine Empire – Michael III (842–867), under the regency of Empress Theodora and Theoktistos (murdered in November)
• Caucasus
  • Principality of Iberia – Bagrat I Kuropalates (830–876)
  • Principality of Kakheti – Samuel (839–861)
• Kingdom of Denmark – Horik II (854–c. 866)
• England (Heptarchy) –
  • Kingdom of East Anglia – Edmund the Martyr (854–869)
  • Kingdom of Kent – Æthelwulf (839–856)
  • Kingdom of Mercia – Burgred (852–874)
  • Kingdom of Northumbria – Osberht (849–862/863)
  • Kingdom of Wessex – Æthelwulf (839–856)
• East Francia – Louis the German (843–876)
  • Duchy of Saxony – Liudolf (844–866)
  • Duchy of Thuringia – Thachulf (849–873)
• Middle Francia – Lothair I (843–855)
  • Duchy of Croatia – Trpimir I (845–864)
• West Francia – Charles the Bald (843–877)
  • County of Angoulême – Turpio (839–863)
  • Duchy of Aquitaine – Ranulf I (854–866)
  • Kingdom of Aquitaine –
    • Pepin II of Aquitaine (854–864)
      1. Charles the Bald (838–855)
      2. Charles the Child (855–866)
  • County of Barcelona – Odalric (852–858)
  • Duchy of Brittany – Erispoe (851–857)
  • Duchy of Gascony – Sans II Sancion of Gascony (836–864)
  • County of Maine – Rorgon II (853–865)
  • County of Poitiers – Ranulf I (854–866)
  • County of Toulouse – Raymond I (852–863)
  • County of Troyes – Odo I (852–858)
  • County of Urgell – Solomon (848–869)
• Ireland – Máel Sechnaill mac Máele Ruanaid, High King of Ireland (846–862)
  • Kingdom of Ailech – Áed Findliath (c. 855–879)
  • Kingdom of Connacht – Mugron mac Máel Cothaid (848–872)
  • Uí Maine –
  • Kingdom of Leinster –
  • Kingdom of Mide – Máel Sechnaill mac Máele Ruanaid (845–862)
  • Kingdom of Munster –
  • Kingdom of Osraige – Cerball mac Dúnlainge (842–888)
  • Kingdom of Ulaid – Matudán mac Muiredaig (839–857)
• Kingdom of Italy –
  1. Lothair I (818–855)
  2. Louis II (855–875)
  • Principality of Benevento – Adelchis (854–878)
  • County of Capua – Lando I (843–861)
  • March of Friuli – Eberhard (846–863)
  • Duchy of Gaeta – Constantine, Hypatus of Gaeta (839–866)
  • Duchy of Naples – Sergius I (840–864)
  • Papal States –
    1. Pope Leo IV (847–855)
    2. Pope Benedict III (855–858)
  • Principality of Salerno – Adhemar (853–861)
  • Duchy of Spoleto – Guy I (842–860)
  • March of Tuscany – Adalbert I (847–886)
  • Republic of Venice – Pietro Tradonico, Doge of Venice (836–864)
• Kingdom of Lotharingia – Lothair II (855–869)
• Great Moravia – Rastislav (846–870)
• Kingdom of Provence – Charles (855–863)
• Scotland
  • Kingdom of the Picts – Kenneth I (848–858)
• Principality of Serbia – Mutimir, Grand Župan (850–891)
  • Strojimir, Župan of Serbia (850–856)
  • Gojnik, Župan of Rascia (850–856)
• Spain –
  • County of Aragon – Galindo Aznárez I (844–867)
  • Kingdom of Asturias – Ordoño I (850–866)
  • Emirate of Córdoba – Muhammad I (852–886)
  • Kingdom of Pamplona – García Íñiguez (851/852–882)
• Wales –
  • Kingdom of Gwynedd – Rhodri the Great (844–878)
  • Kingdom of Powys –
    1. Cyngen ap Cadell (808–855)
    2. Rhodri the Great (855–878)

Middle East

• Abbasid Caliphate – Al-Mutawakkil (847–861)
• Byzantine Empire – Michael III (842–867)

Notes

In this year, Lothair I, Holy Roman Emperor and king of middle Francia, dies. His realm is partitioned for his three sons. Louis II becomes Holy Roman Emperor and king of Italy, Lothair II becomes king of Lotharingia and Charles becomes king of Provence.