Ever since Upper and Lower Egypt were united by warlike means around 3100 B.C., the military played a major role in the empire on the Nile. Wars were seen as a legitimate means to maintain the divine order, to protect the borders of the empire, and sometimes to expand it. At times, Egypt dominated an area that stretched from Nubia to Libya and as far as Asia Minor. Expansion was made possible by new military technologies such as the chariot, which the Egyptians perfected. Yet, the documentary also shows how Egypt, in moments of military weakness, became the target of foreign invaders. During peaceful periods, however, the pharaohs maintained extensive diplomatic contacts with neighboring empires.