Siege of Constantinople (1204) Part of the Fourth Crusade The Entry of the Crusaders in Constantinople, by Eugène Delacroix Date 8–13 April 1204 Location Constantinople, Byzantine Empire Result Decisive Crusader victory Territorial changes Constantinople captured by the Crusaders. Belligerents Byzantine Empire Crusaders Republic of Venice Commanders and leaders Alexios V Doukas Boniface I Enrico Dandolo Strength Byzantines: 15,000 men[1] Byzantines: 20 ships[2] Crusaders: 10,000 men[3] Venetians: 10,000 men[3] Venetians: 210 ships[4] Casualties and losses Unknown Unknown