Cadmus was credited by the ancient Greeks. Cadmus was the son of Agenor and the brother of Europa. He was the founder of the city of Thebes. After Zeus kidnapped Europa, Agenor ordered her brothers -- Cadmus, Phoenix, and Cilix -- to search for her, instructing them not to return until they had found her. It was a hopeless quest, and all three brothers became exiles. Phoenix founded the country of Phoenicia, and Cilix established Cilicia. Cadmus consulted the oracle at Delphi and was told to follow a cow that he would find near the oracle; where the cow lay down to rest, he should found a city. He followed the cow to the future site of Thebes. There he instructed his men to bring water so that he could offer a sacrifice to Athena; however, the men encountered a giant serpent which was sacred to Ares, and they were all killed.