Ptolemy II Philadelphus (Greek: Πτολεμαίος Φιλάδελφος, 309–246 BCE), was the king of Ptolemaic Egypt from 281 BCE to 246 BCE. He was the son of the founder of the Ptolemaic kingdom Ptolemy I Soter and Berenice. He had a half-brother, Ptolemy Ceraunus, who became king of Macedonia in 281 BC, and died in the Gallic invasion of 280-79 BC (see Brennus).