Phrygian Cap: Origins

From Wikipedia:

"The Phrygian cap is a soft, red, conical cap with the top pulled forward, worn in antiquity by the inhabitants of Phrygia, a region of central Anatolia. In artistic representations it signifies freedom and the pursuit of liberty — perhaps by a confusion with the pileus, the manumitted slave's felt cap of ancient Rome — and is sometimes called a liberty cap.

In Antiquity, the Phrygian cap had two connotations: for the Greeks as showing a distinctive Eastern influence of non-Greek "barbarism" (in the classical sense) and among the Romans as a badge of liberty. The Phrygian cap identifies Trojans such as Paris in vase-paintings and sculpture, and it is worn by the syncretic Hellenistic and Roman saviour god Mithras and by the Anatolian god Attis. The twins Castor and Pollux wear a superficially similar round cap called the pileus".