Beginning in 370 BC, the Molossian Aeacidae dynasty built a centralized state in Epirus and began expanding their power at the expense of rival tribes. The Aeacids allied themselves with the increasingly powerful kingdom of Macedon, in part against the common threat of Illyrian raids,. and in 359 BC the Molossian princess Olympias, niece of Arybbas of Epirus, married King Philip II of Macedon. She was to become the mother of Alexander the Great.
Beginning in 370 BC, the Molossian Aeacidae dynasty built a centralized state in Epirus and began expanding their power at the expense of rival tribes. The Aeacids allied themselves with the increasingly powerful kingdom of Macedon, in part against the common threat of Illyrian raids,. and in 359 BC the Molossian princess Olympias, niece of Arybbas of Epirus, married King Philip II of Macedon. She was to become the mother of Alexander the Great.