1203

1203 (MCCIII) was a common year starting on Wednesday of the Julian calendar, the 1203rd year of the Common Era (CE) and Anno Domini (AD) designations, the 203rd year of the 2nd millennium, the 3rd year of the 13th century, and the 4th year of the 1200s decade. As of the start of 1203, the Gregorian calendar was 7 days ahead of the Julian calendar, which was the dominant calendar of the time.

Events

• April 16 – Philip II of France enters Rouen, leading to the eventual unification of Normandy and France.
• April 8 – Congress in Bilino Polje, where Ban Kulin officially declared his allegiance to the Roman Catholic Church and denounced the heresy.
• June 23 – Fleet of the Fourth Crusade enters Bosphorus.
• July 17 – Fourth Crusade captures Constantinople by assault; the Byzantine emperor Alexius III flees from his capital into exile.
• August 1 – Fourth Crusade elevates Alexius IV as Byzantine emperor, after the citizens of Constantinople proclaim as emperor Isaac II Angelus (Alexius IV's father).
• Unknown - John, Duke of Normandy gives the Ecrehos to the Abbey of Val-Richer.

Heads of states

• France – Philippe II, Auguste King of France (reigned from 1180 to 1223)