I can't remember if it was Dr Clarke, or Dr Jeffries, but one day we were talking about some traditional African Civilizations, and I used the word empire, and they corrected me. Empires expand because of violent conquest. Many of our Civilizations grew peacefully... even conflicts many times where armies would meet the chiefs would sit down, and negotiate. If it was determined that fighting was necessary they would pit their best warrior one on one to determine the victor, and even then there would be no killing for the most part. The goal was unity, and prosperity NOT conquest.