AlexiosIV could not pay off the crusaders. They refused to leave Constantinople and raided and plundered the nearby Thracian villages. The Byzantines blamed AlexiosIV for the crusaders' acts. The army rebelled and proclaimed the general Alexios Mourtzouphlos Doukas emperor on 28January 1204. IsaacII had already died, and the new emperor had AlexiosIV murdered, providing the crusaders with an excuse to lay siege to Constantinople again. When they breached the walls on 12April, AlexiosV fled. A group of burghers offered the imperial crown to Theodore's brother, Constantine, but he rejected it. The crusaders captured Constantinople and plundered it completely.