The document summarizes the Inca civilization in Spanish-speaking South America. It discusses that the Incas spoke Quechua and had a knot-based writing system called quipu. It also notes that guinea pigs were domesticated by the Incas and remain an important food source in Peru. The Incas were eventually conquered by the Spanish conquistador Francisco Pizarro in 1532 at the Battle of Cajamarca, where the Incan emperor Atahualpa was taken hostage despite having a larger army.