List of state leaders in 830

Africa

*Ifriqiya (Aghlabids) - Ziyadat Allah I, Emir (817-838)

Asia

*Bohai/Balhae -
*#Da Renxiu/Dae In-su, King of Bohai/Balhae (818-830)
*#Da Yizhen/Dae I-jin, King of Bohai/Balhae (830-857)
*China (Tang Dynasty) - Wenzong, Emperor of Tang China (826-840)
*Gurjara - Nagabhata II, Pratihara King of Gurjara (805-833)
*Japan (Heian Period) - Emperor Junna, Emperor of Japan (823-833)
*Silla - Heungdeok, King of Silla (826-836)

Europe

*Al-Andalus - Abd-ar-rahman II, Emir of Cordoba (822-852)
*Asturias - Alfonso II, King of Asturias (791-842)
*Benevento - Sicone of Aurenza, Prince of Benevento (817-832)
*Bulgaria - Omurtag, Khan of Bulgaria (814-831)
*Dál Riata - Óengus, King of Dalriada (820–834)
*East Anglia¹ - Æthelstan, King of East Anglia (826–839)
*England - Egbert of Wessex, Bretwalda (802–839)
*Frankish Empire - Louis the Pious, Holy Roman Emperor (816-840)
*Ireland - Conchobar mac Donnchada, High King of Ireland (818–831)
*Italy - Lothair I, King of Italy (818-855)
*Northumbria¹ - Eanred, King of Northumbria (810–841)
*Papal States - Gregory IV, Pope (827-844)
*Picts - Óengus (II), King of the Picts (820–834)
*Strathclyde - Arthgal f Dyfnwal, King of Strathclyde (816–872)
*Venice - Giovanni I Participazio, Doge of Venice (829-837)
*Wales - Merfyn "Frych" ap Gwriad, King of Gwynedd (825–844)

Middle East

*Abbasid Caliphate - Al-Ma'mun, Caliph (813-833)
*Byzantine Empire - Theophilus, Byzantine Emperor (829-842)

Notes

#Though East Anglia, Northumbria and Mercia are traditionally perceived to have been in the heptarchy they were largely independent kingdoms until its conquest by the Danes in 869 and 867, respectively - where Mercia was conquered by Wessex in 874. All other members of the heptarchy had been conquered by Wessex and by this time had no form or king