A large part of Piedmont's territory had been overlaining by permafrost every glacial cycles until a
approximately 10.000 years ago and that's the reason why there's not much evidence of human presence from Paleolithic. A small number of traces was found in some areas just outside the prehistoric glaciers' border and in caves. We have traces of settlements from the period between Neolithic and Bronze Age like stilt-houses found at lake of Viverone and at "Lagoni di Mercurago". Besides, prehistoric and protohistoric necropolis are scattered around.
Between Bronze Age and Iron Age even northeastern Piedmont was involved in the great develop of Golasecca culture. But then around IV Century BC came Gauls and melted with Ligurian people based here. When Romans arrived they found a territory inhabited by multiethnic groups made of Celtic-Ligurian people.
Ceasar came first to conquer the region and then Augustus ordered new cities foundation right after conquering the Gauls and to defend mountain crossing points.