Specialization

Military

This is important via the fact you must fight for land and teratory and protect it.

Tiglath-Pileser III of Assyria (ruled 745–727 BC) created Assyria's first standing army. The first known standing armies in Europe were in ancient Greece. The male citizen body of ancient Sparta functioned as a standing army, unlike all other city-states (Poleis), whose armies were citizen militias.

The earliest records of war date around 2700 BC. The ancient Sumerians carved battle records onto stone tablets [source: The Origins of War]. The conflict was between the Sumerians and the neighboring Elamites, who lived in what is now Iran.

The first war in recorded history took place in Mesopotamia in 2700 BCE between Sumer and Elam. The Sumerians, under command of the King of Kish, Enembaragesi, defeated the Elamites in this war and, it is recorded, “carried away as spoils the weapons of Elam.”