Constantine II, Constantius II, and Constans succeed their father Constantine I as co-emperors. The Roman Empire is divided between the three Augusti.[1][2]
1000
Battle of Svolder, Viking Age.[3]
1141
Yelü Dashi, the Liao dynasty general who founded the Qara Khitai, defeats the Seljuq and Kara-Khanid forces at the Battle of Qatwan.
1320
In the Battle of Saint George, the Byzantines under Andronikos Asen ambush and defeat the forces of the Principality of Achaea, securing possession of Arcadia.
1488
Anne becomes sovereign Duchess of Brittany, becoming a central figure in the struggle for influence that leads to the union of Brittany and France.
1493
Battle of Krbava Field, a decisive defeat of Croats in Croatian struggle against the invasion by the Ottoman Empire.