The focale (plural focalia), also known as a sudarium ("sweat cloth"), was a woolen or linen scarf worn by ancient Roman military personnel. It protected the neck from chafing by the armor. The focale is depicted widely in military scenes from Roman art, such as the relief sculpture on the Arch of Septimius Severus in the Roman Forum and Trajan's Column. It is shown loosely knotted in the front, but is sometimes visible with the ends tucked inside the cuirass,