The Order of St John, also known as the Knights Hospitaller, is a medieval Catholic military order founded in the 11th century. Initially established to provide care for sick and injured pilgrims in the Holy Land, the order evolved into a military force that defended Christian territories during the Crusades. Over the centuries, the order expanded its mission to include humanitarian efforts and medical care. Today, the Sovereign Military Order of Malta is a modern successor, focusing on charitable activities and international diplomacy, while maintaining its historical ties to the original Order of St John.