Answer:
In 1533 CE the Inca Empire was the largest in the world. It extended across western South America from Quito in the north to Santiago in the south. However, the lack of integration of conquered peoples into that empire, combined with a civil war to claim the Inca throne and a devastating epidemic of European-brought diseases, meant that the Incas were ripe for the taking. Francisco Pizarro arrived in Peru with an astonishingly small force of men whose only interest was treasure. With superior weapons and tactics, and valuable assistance from locals keen to rebel, the Spanish swept away the Incas in little more than a generation. The arrival of the visitors to the New World and consequent collapse of the Inca Empire was the greatest humanitarian disaster to ever befall the Americas.
