Their power forced Emperor Alexius I Comnenus of the Byzantine Empire to send a call for help to the West in 1095. The West sent the Crusades. These eventually led to the "Sack of Constantinople" in the Fourth Crusade in 1204. Because of this, what was left of the Empire broke into successor states. The winner of these disputes was that of Nicaea. After Constantinople was again conquered by imperial forces, the empire was little more than a Greek state on the Aegean coast. The Eastern Empire came to an end when Mehmed II conquered Constantinople on May 29, 1453. The Ottoman Empire took its place and from 1400 to 1600 was the most powerful empire in the Middle East and ruled at the southern and eastern coast of the Mediterranean Sea.