820 CE
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. 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. Fedelmid mac Crimthainn assumes the kingship as ruler of Munster (modern Ireland).
Geopolitics & Diplomacy
- Fedelmid mac Crimthainn assumes the kingship as ruler of Munster (modern Ireland).source
Religion & Belief
- Caliph Al-Ma'mun appoints Ibrahim al-Ifriqi as Abbasid governor of Yemen. He remains in office until 821.source
- Abbasid caliph Al-Ma'mun appoints Isa ibn Yazid al-Juludi as Abbasid governor of Yemen, for a few months.source
- Caliph Al-Ma'mun appoints Hisn ibn al-Minhal as Abbasid governor of Yemen, for a few months.source
- Caliph al-Ma'mun appoints Abu Nasr ibn al-Sari as Abbasid governor of Egypt.source
Births
- Godfrid Haraldsson, Danish Viking king (approximate date)source
- Ibn Khordadbeh, Persian geographer (approximate date)source
- Ashot I ("the Great"), king of Armenia (approximate date)source
- Álmos, military leader (gyula) of the Hungarians (approximate date)source
- Rhodri the Great, king of Gwynedd (Wales) (approximate date)source
- Grimbald, Frankish Benedictine monk (d. 901)source
- Qusta ibn Luqa, Syrian Melkite physician (d. 912)source
- Anandavardhana, Indian philosopher (d. 890)source
- Hucbert, Frankish nobleman (d. 864)source
- Ranulf I of Aquitaine, Frankish nobleman (d. 866)source
- Adelaide of Tours, Frankish noblewoman (approximate date)source
- Adalbert I, Frankish margrave (approximate date)source
Deaths
- September 14, Li Yong, chancellor of the Tang dynastysource
- 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.source
- December 25, Leo V, emperor of the Byzantine Empire (b. 775)source
- Tutu Chengcui, eunuch and advisor of the Tang dynastysource
- Huangfu Bo, chancellor of the Tang dynastysource
- 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.source
- Causantín mac Fergusa, king of the Pictssource
- Olcobhar mac Cummuscach, abbot of Clonfertsource
- Song Ruoxin, Chinese scholar and poet (b. 768)source
- Xian Zong, emperor of the Tang dynasty (b. 778)source
- Muhammad ibn Idris al-Shafi‘i, Muslim imam (b. 767)source
- Lupo III, duke of Gascony (approximate date)source
- Wang Chengzong, general of the Tang dynastysource
- Adi Shankara, Indian philosopher and theologian (b. 788)source