Pandion II was son and heir of Cecrops II, King of Athens. He was exiled from Athens by the sons of Metion who sought to put him on the throne. Pandion fled to Megara where he married Pylia, daughter of King Pylas. Later, Pylas went into voluntary exile to Messenia, because he had killed his uncle, Bias. Pylas then arranged for his son-in-law to be king of Megara. Pylia bore him four sons, he became father of Aegeus, Pallas, Nisos and Lykos, eventially inheriting the kingdom of Megara when Pylas died.

After this death his sons returned to Athens and drove out the sons of Metion.