The origins of the Epirotes are as complicated as the origins of other greeks. They most likely came out of the same movement of Doric tribes (hence their dialect of Greek), and remained in Epirus until the Romans destroyed the place and enslaved everyone. The tribes were many and they fought within eachother and with Illyrian tribes. The layers of history are mirky all over Epirus with signs of Illyrian and southern greek artifacts found all over.

They have Pelasgian roots, so its up to you if you consider them pre-hellenic or proto-hellenic (both suggestions are popular in certain quarters - feel free to discuss this if you don't mind hijacking your own thread).
I would say all ancient Balkan and Italian nations come from Pelasgian roots.