Alexander Helios was a Ptolemaic prince and son of Pharaoh Cleopatra VII of the Ptolemaic dynasty and Roman triumvir Mark Antony. Alexander's fraternal twin sister was Cleopatra Selene II. Cleopatra named her son after Alexander the Great. His second name in Ancient Greek means "Sun"; this was the counterpart of his twin sister's second name Selene (Σελήνη), meaning "Moon".