Byzantine co-emperor Alexios IV is strangled during the Fourth Crusade on February, 8, 1204 by the usurper Alexios V Doukas (Mourtzouphlus) after being deposed by a popular uprising.
Alexios V, then took a hardline stance against the crusaders. This led directly to the Crusaders' sack of Constantinople a few months later on April 12, 1204.