Cassiopeia is a dwarf galaxy, and also a constillation. The wife of King Cepheus of the Phoenician realm of Ethiopia was beautiful, arrogant and vain. Her name in Greek means "she whose words excel."

She boasts of Cassiopeia that she and her daughter Andromeda were more beautiful than all the Nereids brought down upon them the wrath of Posedion. In order to save the they had to sacrifice their daughter to appeals the gods. Andromeda was chained to a rock at the sea's edge, but was saved by the hero Perseus who later became her husband.

Poseidon thought Cassiopedia should not escape punishment placed her in the heavens in such a way that as she circles the celestial pole she is upside down for half the time.