Zeus the all powerful, and also very amorous god descended on Danae as a shower of gold, and from this union was born a son; this son was to become the legendary Perseus. Acrisius heard the baby crying but was too cowardly to kill him, so he put Danae and Perseus inside a wooden chest and set them adrift on the sea. As luck would have it Zeus was watching over them, and with the aid of Poseidon who calmed the sea, send them to the island of Seriphos. Here they were found and looked after by a fisherman by the name of Dictys. Perseus grew into a fine young man and later in life was sent to kill the Gorgon, "Medusa" by King Polydectes. After his great adventure Perseus and Danae returned to Argos in search of his grandfather, but Acrisius had gone to Larissa. When Perseus arrived there, funeral games were being held and Perseus, being a great athlete, joined in. However, during the discus throwing an accident occurred. By chance the discus Perseus had thrown hit Acrisius and killed him; the prophecy had come true. Perseus would not take over the throne of his grandfather's kingdom, but went to Tiryns and became ruler and founder of the dynasty of Perseidae.
Acrisius was an ancient king of Argos, who, when told of a prophecy, enclosed his daughter Danae in an impenetrable bronze tower (or in other legends a deep cave) because the prophecy was, Acrisius would be killed by his daughter's son. So Danae was kept hidden away from all men, a prisoner of her own father.
Ovid IV, 613.