Calendar overview 821
|Cenwulf , King of Mercia , dies.|
|821 in other calendars|
|Armenian calendar||269/270 (turn of the year July)|
|Buddhist calendar||1364/65 (southern Buddhism); 1363/64 (alternative calculation according to Buddhas Parinirvana )|
|Chinese calendar||58th (59th) cycle|
|Chula Sakarat (Siam, Myanmar) / Dai calendar (Vietnam)||183/184 (turn of the year April)|
|Iranian calendar||199/200 (around March 21)|
|Islamic calendar||205/206 (June 5-6)|
|Jewish calendar||4581/82 (September 1st and 2nd)|
ab urbe condita MDLXXIV (1574)
Diocletian's era : 537/538 (New Year November)
|Seleucid era||Babylon: 1131/32 (turn of the year April)
Syria: 1132/33 (New Year October)
|Vikram Sambat (Nepalese Calendar)||877/878 (turn of the year April)|
Politics and world events
Western and Central Europe
- Ceolwulf I succeeds his late brother Cenwulf as ruler of the Anglo-Saxon kingdom of Mercia .
- The alleged infidelity of Ceadrags to the Franconian Empire by the abodritic princes of the small tribes prompts Emperor Ludwig the Pious to try to reinstate Ceadrag's deposed predecessor Sclaomir as the ruler of the Abodrites . However, he fell ill and died on the way back in Saxony. He is baptized on his deathbed and is thus the first Abodritic tribal prince to be baptized as a Christian.
- Thomas the Slav pretends to be Emperor Constantine VI. and is crowned the anti-emperor of Michael II in the Byzantine Empire . At the end of the year he begins the siege of Constantinople held by Michael . His adopted son and co-regent Konstantios , however, suffers a heavy defeat in Asia Minor. He is captured and executed by beheading. Thomas then raises Anastasios to the new co-emperor.
- The Persian Tahirids win in eastern Iran / Khorassan and Central Asia in fact the independence of the caliph of the Abbasid .
- Peace treaty between the Tibetan King Thri Relpacen and the China of Tang , in which both sides recognize each other as equals
First documentary mentions
- After Arn's death on January 24th, Adalram was made second Archbishop of Salzburg . On October 23, he rededicated the restored Maximilian cell in Bischofshofen , which was repeatedly destroyed in 820 by “ungodly Slavs” (first destruction in the middle of the 8th century ).
- Mid-October: co-emperor Lothar I married in Thionville with Ermengarde , daughter of Count Hugh of Tours .
- January 24th : Arn , Archbishop of Salzburg (* after 740)
- February 11 : Benedict von Aniane , founder of a monastery from southern France (* before 750)
- Borna , ruler of the Dalmatian Croats
- Cenwulf , King of Mercia
- Egbert , Bishop of Lindisfarne
- Sclaomir , velvet ruler of the Abodrites
- Theodulf of Orléans , Visigoth scholar, advisor of Charlemagne and Bishop (around 750 / 760 )