Julius m. Latin Julius, a Roman patrician nomen, of uncertain origin. It was supposed, by the Romans, to have derived from Greek ιουλος 'downy-beared', though there is not much evidence to support this. Another hypothesized origin is Latin *Iovilios 'pertaining to Jove'.
The name of a famous Roman Republic dictator, one of the most influential men in antiquity who was lauded in the Middle Ages, as well as a 4th C pope and saint, and two 16th C popes.
The name came into use in Italy with the Renaissance, and did not reach England until the 16th C. The compound Julius Caesar was also used as a given name after the Renaissance.