Mamas was a shepherd who was martyred under the Roman emperor Aurelian in about 274. According to legend, he was thrown into an arena with wild animals but they refused to touch him.
He is a very obscure saint, seldom represented in art. He is included in one National Gallery altarpiece probably because he was the patron saint of the chief agent in the commission of the painting ('Predella of the Pistoia Santa Trinità Altarpiece').