Feminine form of Silvius. Rhea Silvia was the mother of Romulus and Remus, the founders of Rome. This was also the name of a 6th-century saint, the mother of the pope Gregory the Great. It has been a common name in Italy since the Middle Ages. It was introduced to England by Shakespeare, who used it for a character in his play 'The Two Gentlemen of Verona' (1594). It is now more commonly spelled Sylvia in the English-speaking world.