820s

Byzantine Empire

• December 25 – Emperor Leo V (the Armenian) is assassinated by conspirators in the Hagia Sophia, at Constantinople. Though unarmed, he fights back fiercely but dies of his wounds. He is succeeded by Michael II, the commander of the palace guard (excubitores). Leo's family (including his mother and his wife Theodosia) are exiled to monasteries in Princes' Islands.^[1]

Ireland

• Fedelmid mac Crimthainn assumes the kingship as ruler of Munster (modern Ireland).

China

• Emperor Xian Zong dies from poisoning (due to medicines), after a 14-year reign. He is succeeded by his son Mu Zong, as ruler of the Tang Dynasty.

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