Cassiopeia, depicted as a vain woman, was thoroughly punished by the god Poseidon following a remark she made about her daughter surpassing the Nereids in beauty. An oracle informs Andromeda's desperate parents that their only way of saving themselves from the divine curse is to chain Andromeda to a rock and leave her as a sacrifice to the sea monster who was sent by Poseidon to ravage the whole of Ethiopia. However, the sea monster's mission is ended abruptly by the Greek hero Perseus, returning from having slain the Gorgon Medusa. Perseus encounters the figure of the chained Andromeda, and, invisible due to wearing a helm belonging to the god Hades, slays the sea monster and saves both the princess and the kingdom. Andromeda and Perseus wed, and therefore start the illustrious line of the Perseidae. The myth (and Euripides' retelling of it) state that after Andromeda's death, the goddess Athena turned her into a constellation, bordered by the constellations of her husband, Perseus, and of her