The military order known for white mantles bearing a red cross was the Knights Templar. Also called the Poor Fellow-Soldiers of Christ and of the Temple of Solomon, the order was created in the early 12th century to protect Christian pilgrims travelling to Jerusalem after the First Crusade.
The Templars established their headquarters on the Temple Mount, which helped give them their name. They combined monastic vows—such as poverty, chastity, and obedience—with a military role. Their knights became heavily armed cavalry and one of the most effective fighting forces in the Crusader states.
The white mantle was associated with the Templar knights, while sergeants generally wore darker clothing. The red cross symbolized martyrdom and was authorized for the order in the 1140s. This distinctive uniform is the key clue separating the Templars from other military orders.
The Knights Hospitaller also served pilgrims and fought in the Crusades, but they are more closely associated with caring for the sick and later with a white cross on a red field. The Teutonic Knights typically used a black cross, making them another common mix-up. The Templar order was dissolved in 1312 after the loss of its political and military position in the Holy Land.