829 CE

Emperor Michael II dies after an 8-year reign in Constantinople, and is succeeded by his 16-year-old son Theophilos, as sole emperor of the Byzantine Empire. He continues his father's ideology of iconoclasm. The Bai kingdom of Nanzhao captures the city of Chengdu, in Sichuan Province. Viking chieftain Halfdan the Black becomes king of Agder (modern Norway). He expands his realm through military conquest and political negotiations, dividing the kingdom of Vestfold with his half-brother Olaf.

In the 820s, the 9th century.

Geopolitics & Diplomacy

  • Emperor Louis the Pious appoints his 6-year-old son Charles (by his second wife Judith) as ruler of the Frankish subkingdom Alamannia, enraging his eldest son and co-emperor Lothair I, who begins an insurrection.source
  • Viking chieftain Halfdan the Black becomes king of Agder (modern Norway). He expands his realm through military conquest and political negotiations, dividing the kingdom of Vestfold with his half-brother Olaf.source

Conflict & Security

  • October – Battle of Thasos: Saracens from the newly founded Emirate of Crete almost annihilate the Byzantine fleet at Thasos, close to the coast of Thrace. The Cyclades and other islands in the Aegean Sea are pillaged.source
  • The Bai kingdom of Nanzhao captures the city of Chengdu, in Sichuan Province.source
  • Winter – Battle of the River Dore: Egbert of Wessex leads his army against the Northumbrians as far as Dore, where he clashes with King Eanred of Northumbria.source
  • King Egbert of Wessex invades Mercia, ousts his rival Wiglaf, and attempts to rule directly from Wessex. He is recognized as overlord (bretwalda) of other English kingdoms.source

Religion & Belief

  • Ansgar, Frankish abbot of Corvey (modern Westphalia), is appointed missionary to Sweden by Louis the Pious, at the request of the Swedish king Björn at Haugi.source
  • The city of Wiesbaden (Germany) is first mentioned by Einhard, biographer of former emperor Charlemagne (approximate date).source

Births

  • September 8 – Ali al-Hadi, 10th Shia Imam (approximate date)source
  • Lu Yan, chancellor of the Tang dynasty (died 874)source
  • Al-Nasa'i, Muslim scholar and hadith compiler (approximate date)source
  • Yahya I, Muslim sultan (died 864)source

Deaths

  • June 1 – Li Tongjie, general of the Tang dynastysource
  • July 30 – Shi Xiancheng, general of the Tang dynastysource
  • October 2 – Michael II, emperor of the Byzantine Empire (born 770)source
  • October 2 – Emperor Michael II dies after an 8-year reign in Constantinople, and is succeeded by his 16-year-old son Theophilos, as sole emperor of the Byzantine Empire. He continues his father's ideology of iconoclasm.source
  • Abu al-Razi Muhammad, Muslim governorsource
  • Wei Chuhou, chancellor of the Tang dynasty (born 773)source
  • Giustiniano Participazio, doge of Venice, dies after a 2-year reign, and is succeeded by his younger brother Giovanni Participazio. He continues the work of Giustiniano, in construction of St. Mark's Basilica.source
  • Leibulf of Provence, Frankish noblemansource
  • Zheng Yin, chancellor of the Tang dynasty (born 752)source
  • Giustiniano Participazio, doge of Venicesource
  • 'Umayr ibn al-Walid, Muslim governorsource
  • Muiredach mac Ruadrach, king of Leinstersource
  • Cui Zhi, chancellor of the Tang dynasty (born 772)source
  • Li You, general of the Tang dynastysource