Two of Danaus' fifty daughters (the Danaides) were named Kleopatra (one whose mother was Polyxo the other the daughter of Phoibe or Atlanteia). The two along with their sisters (and half-sisters) were married to sons of King Aigyptos (by his various wives). The night of the mass wedding Kleopatra killed her husband Hermos as did the other Danaids except for Hypermnestra.
When Kleopatra and the other Danaids who had murdered their husbands they were sent to Tartarus and were forced to carry water from the river Styx in a bowls (or jars according to some) with holes over to a tub which leaks at multiple parts. Kleopatra and the others were told only when they filled the tub could they wash away their sins. The Danaids continue this essentially impossible task to this very day.
Spouse & Lovers
"The twelve sons of a Naias Nymphe named Kaliadne [and Aigyptos] drew lots for the daughters of Polyxo, also a Naias [and Danaus]. The sons were named Eurylokhos, Phantes, Peristhenes, Hermos, Dryas, Potamon, Kisseus, Lixos, Imbros, Bromios, Polyktor, and Khthonios; the girls were Autonoe, Theano, Elektra, Kleopatra, Eurydike, Glaukippe, Antheleia, Kleodore, Euippe, Erato, Stygne, and Bryke."
- Pseudo-Apollodorus, Bibliotheca 2. 19 (trans. Aldrich) (Greek mythographer C2nd A.D.)