Alexios IV Angelos
Biography
Alexios IV Angelos was the son of the deposed Byzantine Emperor Isaac II Angelos.
Desperate to reclaim the throne from his uncle, he approached the leaders of the Fourth Crusade. He promised them huge sums of money, military supplies, and the submission of the Byzantine Orthodox Church to the Pope if they helped him.
The crusaders agreed and installed him as co-emperor. However, the Byzantine treasury was nearly empty, and Alexios could not fulfill his extravagant promises.
His attempts to raise money through heavy taxes enraged the citizens of Constantinople, leading to his overthrow and murder. This gave the unpaid crusaders the pretext they needed to sack the city.