John Romer continues his exploration of the Byzantine empire by tracing the extent of its influence abroad. He shows that the desire of its ruler to spread the word of Christianity was not just evangelical but was also a method of subduing Constantinople's potentially dangerous neighbours. By the Middle Ages, Byzantium's influence had spread throughout Europe, but in 1204 the Venetians persuaded an army of Crusaders to divert from Palestine to Constantinople. The city was decimated, the Crusaders took control and for the next fifty years systematically looted it. In 1260 the Crusaders finally left, taking what loot remained with them, leaving what was a wrecked city.