In 1095 Pope Urban II called upon Western Christendom to liberate Jerusalem and eastern Byzantium from Muslim encroachment. They feared the Seljuk Turks (Sunni Muslims) on their borders and wished to reclaim lands taken by them. Urban also had a personal motive for his appeal, he wanted to centralize divided Christendom (the Great Schism). Four huge holy armies (many tempted by Urban’s promise of absolution for service) crossed Bulgaria and converged in Constantinople. They then crossed the Bosporus into Asia Minor and the Holy Land. Bohemond I, Prince of Taranto (southern Italy) virtually assumed command and was so successful in Antioch that he became de facto ruler. Between 1095–99 Crusaders crushed Muslim forces (Seljuk Turks, Fatimid Caliphates and Danishmends) at the sieges of Antioch and Jerusalem. A Pisan fleet of 120 ships made its way to the Holy Land, sacking several Byzantine islands en route, before participating in the siege of Jerusalem. Genoa sent twelve galleys to transport troops to the Holy Land, and led the seaborne attack during the siege of Tripoli. Both these maritime republics were able to exploit the Crusade economically, establishing profitable trading posts in the Levant.