The origins of the order of the Knights Hospitaller are unclear, but it probably emerged around the 1070s in Jerusalem. It started as a religious order that cared for the sick, and later looked after pilgrims to the Holy Land. After the success of the First Crusade in capturing Jerusalem in 1099, many Crusaders donated their new property in the Levant to the Hospital of St John. Early donations were in the newly formed Kingdom of Jerusalem, but over time the order extended its holdings to the Crusader states of the County of Tripoli and the Principality of Antioch. Evidence suggests that in the 1130s the order became militarised when Fulk, King of Jerusalem, granted the newly built castle at Beth Gibelin to the order in 1136. A papal bull from between 1139 and 1143 may indicate the order hiring people to defend pilgrims. There were also other military orders, such as the Knights Templar, that offered protection to pilgrims.