The Danaides were the fifty daughters of Danaus. They were to marry the fifty sons of Danaus' twin brother Aegyptus, a mythical king of Egypt. In the most common version of the myth, all but one of them killed their husbands on their wedding night and were condemned to spend eternity carrying water in a sieve or perforated device. In the classical tradition, they come to represent the futility of a repetitive task that can never be completed.
Danaus did not want his daughters to go ahead with the marriages to his brother's sons and he fled with them in the first boat to Argos.
Danaus agreed to the marriage of his daughters only after Aegyptus came to Argos with his fifty sons in order to protect the local population, the Argives, from any battles. The daughters were ordered by their father to kill their husbands on the first night of their weddings and this they all did with the exception of one, Hypermnestra, who spared her husband Lynceus because he respected her desire to remain a virgin. Danaus was angered that his daughter refused to do as he ordered and took her to the Argives courts. Lynceus killed Danaus as revenge for the death of his brothers and he and Hypermnestra started a dynasty of rulers in Argos.
The other fourty-nine daughters remarried by choosing their mates in footraces. Some accounts tell that their punishment was in Tartarus, being forced to carry a jug to fill a bathtub without a bottom to wash their sins of. Because the water was always leaking, they would forever try to fill the tub.