Her father knows nothing about brotherhood

Despite the fact that the word brother is sometimes used to denote a close friend, the twins Acrisius and Proetus ₁ never knew anything about brotherhood or friendship. For they quarrelled with each other while they were still in the womb, and after they were born they continued their efforts to destroy one another. That is why when they were grown up, being unable to share the kingdom, they waged war for the throne of Argos, which they could have peacefully inherit from their father King Abas ₂, son of Lynceus ₂, the only son of Aegyptus ₁ who survived the massacre staged by the DANAIDS.

War and division of Argos

Being endowed with such a genius for enmity, the twins were the first to invent shields in the course of the war; and Acrisius, having won the first match, drove his brother from Argos. But Proetus ₁, who married a foreign princess while he was in exile, returned with an army of Lycians that his father-in-law provided, and occupied Tiryns. Having then come to a standstill, the twins finally reached the agreement they had failed to reach in the womb; and the Argive territory had to be divided, Acrisius receiving Argos, and Proetus ₁ receiving Tiryns. Acrisius married Eurydice ₂, or perhaps Aganippe ₂, and had by one of them a daughter Danae. But as he was not satisfied with this offspring only, he asked the Oracle at Delphi how he should get male children. The oracle, which not so seldom comes with unwanted news, answered that he was not to have a son, but that his daughter Danae would give birth to a son, who would kill him. Having heard this alarming prophecy, Acrisius built a brazen chamber under the ground, or perhaps a stone-walled prison, and there he guarded Danae, apparently believing that youth and beauty can be caged. And if someone had guessed that such a measure would have no effect, he would have been right; for Danae was seduced in her prison, either by her uncle Proetus ₁, or by Zeus himself, who came to her in the shape of a stream of gold pouring from the roof into her lap. Yet some have explicitly said that:

"... no one is named as the mortal father of Perseus, as Amphitryon is named father of Heracles ..." (Herodotus, History 6.53.2).

Cast into the sea

Very few would believe that Danae was seduced by the god, and Acrisius did not believe it either. But as he instead believed in the Oracle, when Danae gave birth to Perseus ₁, Acrisius put his daughter and the child into a chest, and banishing them from the kingdom, cast the chest into the sea. The chest was washed ashore in Seriphos, one of the Cyclades islands, where Danae and her child were found by Dictys ₁, who was fishing. After some time (for Perseus ₁ was already grown up), King Polydectes ₁ of Seriphos, who also was brother of Dictys ₁, fell in love with Danae, but for some reason Perseus ₁ opposed him, and he could not get her. In order to find a remedy to this annoying circumstance, Polydectes ₁ sent Perseus ₁ to fetch the head of Medusa ₁, hoping to take care of Danae while her son was away. However, while Perseus ₁ was away, Polydectes ₁ was resisted, not only by Danae, but also by his own brother Dictys ₁. And when Perseus ₁, after having killed a couple of monsters and staged a massacre in the Ethiopian court, returned to Seriphos, he found that Dictys ₁ and Danae had taken refuge in a temple in an attempt to escape the violence of Polydectes ₁, who wished to marry Danae against her will. This is why Perseus ₁ went to the king's palace, where Polydectes ₁ and his friends were gathered, and turned them all into stone, by showing them the head of Medusa ₁. After having thus filled the palace with new statues (it is said that even the island was made rocky by the head of Medusa ₁), he appointed Dictys ₁ king of Seriphos.

Oracle fulfilled

Perseus ₁ wished now to come to terms with Acrisius, and for this purpose he traveled to Argos, taking with him his mother Danae and Andromeda, the wife he had won in Ethiopia. But when Acrisius heard that Perseus ₁ was on his way, he, remembering the oracle, went away. Shortly after, King Teutamides of Larissa in Thessaly held athletic games in honor of his dead father; and to these games came both Acrisius and Perseus ₁ to compete. It was then that the oracle found its fulfilment; for Perseus ₁, who had engaged in the pentathlum, threw the quoit and, having struck Acrisius in the foot, killed him instantly.

Second opinion about Polydectes ₁

However, others have not described Polydectes ₁ as a tyrant. Instead they say that when the chest arrived to Seriphos, Polydectes ₁ married Danae, bringing up Perseus ₁ in the temple of Athena. They say that when Acrisius discovered that the exiles were staying at Polydectes ₁'s court, he came to the island, and that then Polydectes ₁ interceded for them, making Perseus ₁ swear an oath to his grandfather that he would never kill him. When this agreement had been reached Acrisius was detained in the island by a storm and, at that time, Polydectes ₁ died. It was, they say, during the funeral games in honor of Polydectes ₁, that the wind blew a discus from Perseus ₁'s hand, hitting Acrisius' head and killing him. After the burial, they add, Perseus ₁ set out for Argos, with his mother and his wife, and took possession of his grandfather's kingdom. But, they insist, Perseus ₁ did not kill Acrisius of his own will, but Acrisius died in accordance with the will of the gods; for his fate had been predicted by the Oracle at Delphi.

Danae's death has never been reported.