Byzantine Emperor Michael II can defeat the opposing Emperor
Thomas the Slav , take prisoner and execute him.
|823 in other calendars|
|Armenian calendar||271/272 (turn of the year July)|
|Buddhist calendar||1366/67 (southern Buddhism); 1365/66 (alternative calculation according to Buddha's Parinirvana )|
|Chinese calendar||58th (59th) cycle|
|Chula Sakarat (Siam, Myanmar) / Dai calendar (Vietnam)||185/186 (turn of the year April)|
|Iranian calendar||201/202 (around March 21)|
|Islamic calendar||207/208 (May 15/16)|
|Jewish calendar||4583/84 (9/10 September)|
from urbe condita MDLXXVI (1576)
Diocletian's era : 539/540 (New Year November)
|Seleucid era||Babylon: 1133/34 (turn of the year April)
Syria: 1134/35 (turn of the year October)
|Vikram Sambat (Nepalese Calendar)||879/880 (turn of the year April)|
Politics and world events
- April 5th : Pope Paschalis I crowns Lothar I as co-emperor in the Frankish empire, which his father Ludwig the Pious rules.
Bulgarian Khans Omurtag had to break off the siege of Constantinople , tries to restart the siege, but is defeated by the troops of Emperor Michael II in May and pushed back to a few permanent places in Thrace .
- October: Thomas the Slav is handed over to Emperor Michael II by his own people and executed by impalation. His co-regent Anastasios suffers the same fate. Two supporters of Thomas, Choireas and Gazarenos Colony , can stay in Asia Minor for a few more months.
- Saracens from the western Mediterranean invade the island of Crete, part of the Byzantine Empire .
- Viking Age : Vikings try to conquer the Irish monastery island of Skellig Michael .
- Beornwulf takes the throne of Mercia .
First documentary mentions
- Founding of Mashhad , one of the seven holy places of Shiite Islam, on the site of the tomb of ʿAlī ibn Mūsā ar-Ridā
- June 13 : Charles II the Bald , West Franconian King and Emperor († 877 )
- Muhammad I , Emir of Cordoba († 886 )