Cadmus

Cadmus was a Greek mortal king.

Abduction of Europa
Cadmus' sister, Europa, was abducted by Zeus and was taken to Crete. Their father, Agenor, instructed his sons to go out and look for her and to not return until they found her.

Founding of Thebes
During his wanderings, Cadmus came to the oracle of Delphi and it told him to follow a cow that would show him where he should built a town by sitting down. This led Cadmus to found the city of Thebes. Cadmus then wanted to sacrifice the cow to Athena so he sent some of his companions to a nearby spring of water where they were killed by the Ismenian Dragon. This led Cadmus to go and slay the dragon. By the advice of Athena, Cadmus sowed the dragon's teeth into the ground and a race of warrior men, the Spartoi, rose from the ground. Cadmus threw a stone into the crowd and they all began to fight until only five were still alive. These five became the founders of the five most noble families of Thebes.

Because the dragon that Cadmus slayed was sacred to Ares, he had to serve him for eight years. At the end of those eight years, Cadmus was given Harmonia, the goddess of concord, as his bride. At the wedding of Cadmus and Harmonia, all the gods attended and brought gifts. Hephaestus, who disliked that Harmonia was the daughter of his wife, Aphrodite, and Ares, gave her a cursed necklace that doomed all her descendants to lives of misery.

Transformation
Cadmus continued to suffer from his killing of the Ismenian Dragon and he once said that if the dragon was so important to the gods, he wished that life for himself. He immediately was turned into a serpent but Harmonia begged the gods to turn him back, which they did.

In other sources, Cadmus and Harmonia were turned into serpents after their death and they remained near their tombs to guard them.

Relationships

 * Parents: Agenor and Telephassa
 * Spouse(s): Harmonia
 * Children with Harmonia: Semele, Ino, Agave, Autonoe, Polydorus