Events

• April 16 – Philip II of France enters Rouen, leading to the eventual unification of Normandy and France.

• April 8 – Congress of Bilino Polje: Ban Kulin officially declares his allegiance to the Roman Catholic Church and denounces heresy.

• June 23 – The Fleet of the Fourth Crusade enters the Bosphorus.

• July 17 – The armies of the Fourth Crusade capture Constantinople by assault; the Byzantine emperor Alexius III flees from his capital into exile.

• August 1 – The Fourth Crusade elevates Alexius IV as Byzantine Emperor, after the citizens of Constantinople proclaim as emperor Isaac II Angelus (Alexius IV's father).

• William de Braose, Fourth Lord of Bramber becomes the guardian of Arthur I, Duke of Brittany, and is possibly responsible for his death.

• Minamoto no Sanetomo becomes shogun of the Kamakura Shogunate

• Battle of Basiani: The Georgians defeat a Muslim coalition.

• The Almohads begin the conquest of the Balearic Islands.

• The Temple of Nataraja is completed by Chidanbaram of India.

Births

• Peter II of Savoy (d. 1268)

Deaths

• Peter of Blois, French poet and diplomat (b. 1135)

• Arthur I, Duke of Brittany (b. 1187)

• Dafydd ab Owain Gwynedd, King of Gwynedd

Heads of states

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

1203 in Fiction

• Founding of the Quidditch team the Holyhead Harpies