The Order of Saint Lazarus of Jerusalem, also known as the Leper Brothers of Jerusalem or simply as Lazarists, was a Catholic military order founded by Crusaders in the Latin Kingdom of Jerusalem and led by a Grand Master. While the monastic order is believed to have been formally established in the 1130s as a hospitaller body, documentary evidence confirms that its central edifice, a leper hospital dedicated to Saint Lazarus, was a functioning concern as early as 1073. Unlike other major military orders, the Order of Saint Lazarus was centered on the charism of caring for those afflicted with leprosy, and its early membership was largely composed of leprous knights who had been forced to leave the Knights Templar or Knights Hospitaller. Despite its primarily medical and charitable focus, the Order assumed a military role in the 13th century to defend the Holy Land, and received canonical recognition as an order of chivalry from Pope Alexander IV in 1255.