King Acrisios of Argos was a hard, selfish man. He hated his brother, Proitos, Who later drove him from his Kingdom, and he cared nothing for his daughter, Danae. His whole heart was set on having a son who should succeed him, but since many years went by still had only the one daughter, he sent a message to the oracle of Apollo to ask whether he should have more children of his own.

The answer of the oracle was terrible. Acrisios should have no son, but his daughter, Danae, would bear him a grandchild who would grow up to kill him. At these words Acrisios was beside himself with fear and rage. Swearing that Danae should never have a child to murder him, he had a room built underground and lined all with brass. Thither he conducted Danae and shut her up, bidding her spend the rest of her life alone.