820

820 in other calendars

Gregorian calendar	820 DCCCXX
Ab urbe condita	1573
Armenian calendar	269 ԹՎ ՄԿԹ
Assyrian calendar	5570
Balinese saka calendar	741–742
Bengali calendar	227
Berber calendar	1770
Buddhist calendar	1364
Burmese calendar	182
Byzantine calendar	6328–6329
Chinese calendar	己亥年 (Earth Pig) 3516 or 3456     — to — 庚子年 (Metal Rat) 3517 or 3457
Coptic calendar	536–537
Discordian calendar	1986
Ethiopian calendar	812–813
Hebrew calendar	4580–4581
Hindu calendars
- Vikram Samvat	876–877
- Shaka Samvat	741–742
- Kali Yuga	3920–3921
Holocene calendar	10820
Iranian calendar	198–199
Islamic calendar	204–205
Japanese calendar	Kōnin 11 (弘仁１１年)
Javanese calendar	716–717
Julian calendar	820 DCCCXX
Korean calendar	3153
Minguo calendar	1092 before ROC 民前1092年
Nanakshahi calendar	−648
Seleucid era	1131/1132 AG
Thai solar calendar	1362–1363
Tibetan calendar	ས་མོ་ཕག་ལོ་ (female Earth-Boar) 946 or 565 or −207     — to — ལྕགས་ཕོ་བྱི་བ་ལོ་ (male Iron-Rat) 947 or 566 or −206

Events

Politics and world events

Central Europe

• The Zürichgau, originally a subdivision, is separated from the Thurgau around 820 and becomes an Alemannic Gau. Ruadker is named as the first count of the Zürichgau.

Byzantine Empire

• December: A plot against Emperor Leo V the Armenian is discovered. The conspirators, led by Michael II, are imprisoned and sentenced to death.
• December 25: Supporters of the imprisoned Michael murder Emperor Leo V. Michael II becomes Byzantine Emperor and establishes the Amorian dynasty. Leo's four sons, including co-emperor Constantine, are spared, but are exiled with their mother to the island of Prote in the Sea of Marmara. There, they are forced to become monks and are castrated to prevent them from becoming possible successors to the throne. They are allowed to keep part of their property.

First documented mentions

• Hasel and Fällanden are mentioned in documents for the first time.
• Drenthe is mentioned in a document for the first time.
• The red dragon is first known to have been used as a symbol of Wales.

Deaths

• Religious philosopher Adi Shankara dies.