List of state leaders in 838

837 state leaders – Events of 838 – 839 state leaders – State leaders by year

Asia

• China (Tang Dynasty) - Wenzong, Emperor of Tang China (826–840)
• Gurjara - Mihira Bhoja I, Pratihara King of Gurjara (c. 836–886)
• Japan (Heian Period) - Emperor Nimmyō, emperor of Japan (833–850)
• Korea (North South States Period)
  • Balhae - Dae Ijin, King of Balhae (830–857)
  • Silla -
    1. Huigang, King of Silla (836–838)
    2. Minae, King of Silla (838–839)

Europe

• Bulgaria - Presian, Khan of the Bulgars (836–852)
• Byzantine Empire - Theophilos (829–842)
• Caucasus
  • Principate of Iberia - Bagrat I Kuropalates (830–876)
  • Principality of Kakheti - Vache, Prince of Kakheti (827–839)
• Kingdom of Denmark - Horik I (813–854)
• England (Heptarchy) - Egbert of Wessex, Bretwalda (829–839)
  • Kingdom of East Anglia - Æthelstan (826–c. 839)
  • Mercia - Wiglaf, King of Mercia (830–839)
  • Northumbria - Eanred, King of Northumbria (810–841)
  • Wessex - Egbert, King of Wessex (802–839) and King of Kent (825–839)
• Frankish Empire -
  • Louis the Pious, King of the Franks and Senior Holy Roman Emperor (814–840)
  • Lothair I, King of Italy and Junior Holy Roman Emperor (817–855)
  • Aquitaine -
    1. Pepin I of Aquitaine, King of Aquitaine (817–838)
    2. Pepin II of Aquitaine, King of Aquitaine (838–851/852)
    3. Charles the Bald, King of Aquitaine (838–855)
    • Auvergne - Guerin of Provence, Count of Auvergne (819–839)
    • Gascony - Sans II Sancion of Gascony, Count of Gascony (836–864)
    • Toulouse - Bernard of Septimania, Count of Toulouse (835–842)
  • County of Barcelona - Bernard of Septimania (835–844)
  • Bavaria - Louis the German, King of Bavaria (817–843)
  • Littoral Croatia - Mislav of Croatia, Duke of Littoral Croatia (835–845)
  • County of Maine - Rorgon I (832–840)
  • County of Nantes - Ricwin (831–841)
  • Poitiers - Emenon, Count of Poitiers (828–839)
  • County of Urgell - Sunifred I (834–848)
• Ireland - Niall Caille, High King of Ireland (833–846)
  • Ailech - Niall Caille, King of Ailech (823–846)
  • Connacht - Cathal mac Muirgiussa, King of Connacht (833–839)
  • Uí Maine - Cathal mac Ailell, King of Uí Maine (834–844)
  • Leinster -
    1. Bran mac Fáeláin, King of Leinster (835–838)
    2. Ruarc mac Brain, King of Leinster (838–847)
  • Kingdom of Mide - Máel Ruanaid mac Donnchada Midi (833–843)
  • Munster - Feidlimid mac Cremthanin, King of Munster (820–847)
  • Ulaid - Muiredach mac Eochada, King of Ulaid (825–839)
• Italy - Lothair I, King of Italy and Junior Holy Roman Emperor (818–855)
  • Principality of Benevento - Sicard of Benevento (832–839)
  • Papal States - Pope Gregory IV (827–844)
  • Duchy of Spoleto - Berengar (836–841)
  • Venice - Pietro Tradonico, Doge of Venice (836–864)
• Pannonian Croatia - Ratimir, Duke of Pannonian Croatia (829–838)
• Scotland
  • Picts - Uen, King of the Picts (836/837–839)
• Serbia - Vlastimir, Zupan of Serbia (835–850)
• Spain -
  • County of Aragon - Galindo Garcés (833–844)
  • Kingdom of Asturias - Alfonso II (791–842)
  • Caliphate of Córdoba - Abd-ar-rahman II (822–852)
  • Kingdom of Pamplona - Iñigo Arista (824–851/852)
• Wales -
  • Kingdom of Gwynedd - Merfyn Frych (825–844)
  • Kingdom of Powys - Cyngen ap Cadell (808–855)