What is "molossians"

The Molossians were an ancient Greek tribal state and kingdom that inhabited the region of Epirus since the Mycenaean era. On their northwest frontier, they had the Chaonians and on their southern frontier the kingdom of the Thesprotians; to their north were the Illyrians. The Molossians were part of the League of Epirus until they sided against Rome in the Third Macedonian War (171–168 BC). The result was disastrous, and the vengeful Romans enslaved 150,000 of its inhabitants and annexed the region into the Roman Republic.