April 9th

According to historians this are some issues that occured on April 9 of the following years:

193 - Septimius Severus is proclaimed Roman Emperor by the army in Illyricum (in the Balkans).
475 - Byzantine Emperor Basiliscus issues a circular letter (Enkyklikon) to the bishops of his empire, supporting the Monophysite christological position.
715 - Constantine ends his reign as Catholic Pope
1241 - Battle of Liegnitz - Mongol armies defeat Poles & Germans
1388 - Battle of Näfels; Glarius Swiss defeat Habsburg (Austrian) army
1413 - Henry V is crowned King of England.
1440 - Christopher of Bavaria is appointed King of Denmark.