1204
Year 1204 was a leap year starting on Thursday of the Julian calendar.Events
- April 13 - Fourth Crusade: The Crusaders take Constantinople by storm, and pillage the city for 3 days. Forces of the Republic of Venice seize the antique statues that will become the horses of Saint Mark.
- May 16 - Baldwin, Count of Flanders is crowned emperor of the Latin Empire a week after his election, by the members of the Fourth Crusade.
- Theodore I Laskaris flees to Nicaea after the capture of Constantinople, and establishes the Empire of Nicaea; Byzantine successor states are also established in Epirus and Trebizond.
- Boniface I, Marquess of Montferrat, a leader of the Fourth Crusade, founds the Kingdom of Thessalonica.
- The writings of French theologian Amalric of Bena are condemned by the University of Paris, and Pope Innocent III.
- Tsar Kaloyan is recognized as king of Bulgaria by Pope Innocent III, after the creation of the Bulgarian Uniate church.
- Valdemar II of Denmark is recognized as king in Norway.
- Angers and Normandy are captured by Philip II of France.
- The Cistercian convent of Port-Royal-des-Champs is established.
- The district of Cham becomes subject to Bavaria.
- Hermann I, Landgrave of Thuringia submits to Philip of Swabia.
- Beaulieu Abbey is founded.
- The Channel Islands of Guernsey and Jersey decide, after a plebiscite of wealthy land owners, to remain with the English crown, after Normandy is recaptured by Philip II of France.
Births
- April 14 - Henry I, king of Castile
- Haakon IV of Norway
- Henry Raspe, Landgrave of Thuringia
- Maria of Courtenay, Empress regent of Nicaea
- Abû 'Uthmân Sa'îd ibn Hakam al Qurashi, Ra'îs of Manûrqa
- Alice of Schaerbeek
Deaths
- January 1 - King Haakon III of Norway
- January - Isaac II Angelos, Byzantine emperor
- February 8 - Alexios IV Angelos, Byzantine emperor
- April 1 - Eleanor of Aquitaine, Sovereign Duchess Regnant of Aquitaine, queen of France and England
- August 11 - King Guttorm of Norway
- August 14 - Minamoto no Yoriie, Japanese shōgun
- September 30 or November 30 - Emeric, King of Hungary
- c. October 21 - Robert de Beaumont, 4th Earl of Leicester, English nobleman
- November - Ban Kulin, ruler of Bosnia
- December 12 - Maimonides, Spanish rabbi and philosopher
- December 22 – Fujiwara no Shunzei, Japanese waka poet
- date unknown - Suleiman II, Sultan of Rûm
- probable - Amalric of Bena, French theologian