The Knights of St John of Jerusalem known also as Knights of Rhodes and as Knights of Malta, was initially a religious and military order founded in Jerusalem in 7th BC, after the formation of the Latin Kingdom of Jerusalem. They took part in all the wars in the Holly Land against the Moslems. Gerard, their first leader, was called rector; later heads of the order were called grand masters. In 1308 they left the Holy Land with the collapse of the Crusader states and occupied the island of Rhodes. There they formed a territorial state until in 1522, when they surrendered the city and its inhabitants to the Ottoman Turks. They were permitted to leave and in 1530 they formed the order of the Knights of Malta. When Napoleon seized Malta, they were forced once again, to leave their occupied territory. The convent was moved to Trieste in 1798 and later, in 1834, to Rome. Today they form a religious community and maintain hospitals and medical centers. The grand master still holds a church rank equal to that of cardinal.