Pileus

Pileus, a bonnet, or cap, of woven wool; sometimes called a freedom cap and used a symbol of freedom from ancient times to the modern era.  Pilei (plural for pileus) and pilei with stars above them are frequently used to represent the Dioskouroi.  Pilei also represent freedom because freed slaves wearing pilei would follow their former master in his bier at his funeral (demonstrating his magnanimity and bringing him prestige).  The form of the Roman pilei was varied; some were round, others resembled a helmet, some were shaped almost like a pyramid, and some were of a more depressed form.  The Romans for the most part went without hats, except on religious occasions, the saturnallia, or when on journeys or military service.  The pileus was also sometimes worn by the sick, old men and newly freed slaves (the latter in token of liberty).

Pileus

The pileus liberatis was a Phrygian soft woven wool cap often used as a symbol of freedom. The form of the Roman pilei (plural for pileus) was varied; some were round, others resembled a helmet, some were shaped almost like a pyramid, and some were of a more depressed form. Pilei and pilei with stars above them also represent the Dioskouroi. The pileus was sometimes worn by the sick, old men and newly freed slaves (the latter in token of liberty). Freed slaves wearing pilei would follow their former master in his bier at his funeral (demonstrating his magnanimity and bringing him prestige). When Salturnius conquered Rome in 263 B.C. he raised a pileus liberatis on a pikestaff to announce the slaves who joined his fight would be freed. This liberty cap became a symbol of freedom for the Romans. It was a popular symbol during the French Revolution and was also depicted on some early U.S. coins.