The Incas conquered a huge number of neighboring peoples in a short time span, between 1438 and 1532; each of these groups had its own language or dialect, and the Incas wanted to integrate those new territories into their hyperefficient organizational network quickly. read more
Of all the major Bronze Age civilizations, only the Inca of South America appeared to lack a written language, an exception embarrassing to anthropologists who habitually include writing as a defining attribute of a vibrant, complex culture deserving to be ranked a civilization. read more