Knight Hospitalier. The Order of Knights of the Hospital of Saint John of Jerusalem arose in the early 12th century, at the time of the great monastic reformation, as a group of individuals associated with an Amalfitan hospital in the Muristan district of Jerusalem, dedicated to John the Baptist and founded around 1023 by Gerard Thom to provide care for sick, poor or injured pilgrims coming to the Holy Land. After the conquest of Jerusalem in 1099 during the First Crusade, the organization became a religious and military order under its own Papal charter, charged with the care and defense of the Holy Land. Following the conquest of the Holy Land by Islamic forces, the knights operated from Rhodes, over which they were sovereign, and later from Malta, where they administered a vassal state under the Spanish viceroy of Sicily. The knights were weakened in the Protestant Reformation, when rich commanderies of the order in northern Germany and the Netherlands became Protestant and largely separated from the Roman Catholic main stem, remaining separate to this day. Engraving from "Monasticon Anglicanum, or the History of the Ancient Abbies, Monasteries, Hospitals, ..." by William Dugdale, 1718.