- as a collection point for resources to trade (Sarazm in Central Asia) — [[The Horse The Wheel And Language by David Anthony#ch16p418 The Importance of Tin]] - as a way to bleed off unsustainable population (Greece, Polynesia). [[Unusual Governments To Take Inspiration From#Theocratic Governments]] & [[Beyond the Blue Horizon by Brian Fagan]], although note that [[ancient greek colonization was more like ... moving]] - need to control access points for trade goods (Carthage, Greece, Swahili Coast city-states). [[The Civilizations of Africa by Christopher Ehret#ch05p164-165 Social and Political Consequences of the Commercial Revolution]] - to expand control of a nearby territory (Egypt). [[The Civilizations of Africa by Christopher Ehret#ch05p164-165 Social and Political Consequences of the Commercial Revolution]]