Ptolemy II Philadelphus (
Greek: ,
Ptolemaîos Philádelphos, 309–246 BCE) was the king of
Ptolemaic Egypt from 283 to 246 BCE. He was the son of the founder of the Ptolemaic kingdom Ptolemy I Soter and
Berenice, and was educated by
Philitas of Cos. He had two half-brothers,
Ptolemy Keraunos and
Meleager, who both became kings of
Macedonia (in 281 BCE and 279 BCE respectively), and who both died in the
Gallic invasion of 280–279 BCE. Ptolemy was first married to
Arsinoë I, daughter of
Lysimachus, who was the mother of his legitimate children; after her repudiation he married his full sister
Arsinoë II, the widow of Lysimachus.