- Knights of the Hospital
- Also known as the Knights Hospitaller or Knights of Rhodes. Originally formed during the First Crusade as a religious order to provide medical care for Christians in Jerusalem, it soon became a military monastic order. The Knights took control of Rhodes in 1309, but lost the island to Ottoman Sultan Suleiman the Magnificent in 1522. They moved their headquarters to the island of Malta and became known as the Knights of Malta, and Knights of St. John.