Zeus saw Europa gathering flowers and immediately fell in love with her. Zeus transformed himself into a white bull and carried Europa away to the island of Crete. He then revealed his true identity and Europa became the first queen of Crete. Agenor, meanwhile, sent Europa's brothers, Cadmus, Phoenix and Cilix to find her.
Cadmus went on a quest to find his disappeared sister. Upon consultation of the oracle of Delphi, he was advised to travel until encountering a cow. He was to follow this cow and to found a city where the cow would lie down; this city became Thebes.
Virgil I, 338