Fourth Crusade
Pretenders and Contenders
Alexius IV quickly found Constantinople an unpleasant place. By the time he had handed out gifts all around, he did not have enough money to pay the Venetians. The tax he levied to raise the money was bitterly resented by the citizens, who didn't much like the Westerners who were infesting their streets anyway. The Franks were rude and violent, didn't pay their bills, and sometimes pillaged the countryside. One group decided to burn down a mosque, but the flames got out of control and a whole section of the city burned. For their part, the Franks were angry that the great promises made by Alexius were not being fulfilled. They had turned aside from their true destination, risked excommunication, and for what? To be duped once again by the wily and treacherous Greek.
Isaac II was blind and old and took little part in government. As the months passed, Alexius IV likewise steadily withdrew from public life, spending more and more time in the palace. A foreign army stalked the city, the citizens were angry and restless, and no one was steering the ship. In this atmosphere, yet another Alexius stepped forward, this one known to the Crusaders as 
Alexius Murzuphlus.
This Alexius was a member of the Ducas family and was a descendant of Alexius Comnenus. More importantly, he positioned himself as the leader of the anti-Latin faction and so rode a popular tide. Late in January 1204, he seized power openly, murdered Alexius IV and put Isaac back in prison again, where the poor man soon died. As Alexius V, he reinforced the city's defenses, most of the Latins having meantime withdrawn from the city to their camp across the Golden Horn. There was now open skirmishing between the Greeks and the Latins.