On this date, September 3rd, in medieval history:
- 1189 – Richard I (the “Lion-Heart”) crowned King of England
- 1260 – The Egyptian Mamluks defeat the Mongols at the Battle of Ain Jalut, marking the first time the Mongols had ever been decisively defeated, according to some historians
- 1346 – Edward III, King of England, lays siege to Calais