At various times, the hat was used as a collective symbol of freedom beyond just manumission of individuals. Not long after the murder of Julius Caesar on the Ides of March in 44 BCE, one of the assassins, Brutus, minted coins with a freedom cap between two daggers as a sign of freedom from the tyranny of the dictator.
Crowds could rejoice in their freedom from an oppressive emperor by donning the freedman’s cap. This is the story we are told by the imperial historian Suetonius, who notes that upon the death of the emperor Nero in June of 68 CE: “such was the public rejoicing that the people put on liberty-caps and ran about all over the city.” This was the birth of the red hat in the Mediterranean, at least, as a symbol of both resistance and freedom from oppression.