475 - Byzantine Emperor Basiliscus issues a circular letter (Enkyklikon) to the bishops of his empire, supporting the Monophysite christological position.
Apr 9, 715
715 - Constantine ends his reign as Catholic Pope
Apr 9, 1241
Battle of Liegnitz
1241 - Battle of Liegnitz - Mongol armies defeat Poles & Germans
Apr 9, 1388
Battle of Näfels;
1388 - Battle of Näfels; Glarius Swiss defeat Habsburg (Austrian) army
Apr 9, 1413
1413 - Henry V is crowned King of England.
Apr 9, 1440
Christopher of Bavaria
1440 - Christopher of Bavaria is appointed King of Denmark.
Apr 9, 1454
Milan and Venice
1454 - Milan and Venice sign peace of Lodi
Apr 9, 1474
Breisach land guardian
1474 - Breisach land guardian Peter von Hagenbach throws out Walloon/Italians
Apr 9, 1483
1483 - Edward V (aged 12) succeeds his father Edward IV as king of England. He was never crowned, and disappeared, presumed murdered, after incarceration in the Tower of London with his younger brother Richard (the "Princes in the Tower")
193 - Septimius Severus is proclaimed Roman Emperor by the army in Illyricum (in the Balkans).