Tyrrhenus was a son of the Lydian king Atys. He gave his name to the Tyrrhenians (the people known later as Etruscans) and to the Tyrrhenian Sea. His name is also spelt Tyrsenus, which suggests that it may derive from tyrsis, 'tower' (compare Tyro). This would be a fitting name for a prince, whose family lived in a walled city.