Empires, bureaucracies and religion arise from war

Intro:

Computer simulation shows that conflict fuelled political consolidation in ancient and medieval history.

War drove the formation of complex social institutions such as religions and bureaucracies, a study suggests. The institutions would have helped to maintain stability in large and ethnically diverse early societies. The study authors, who tested their theories in simulations and compared the results with historical data, found that empires arise in response to the pressure of warfare between small states.