“So great was the terror of the Indians at seeing the Governor force his way through them, at hearing the fire of the artillery, and beholding the charging of horses, a thing never before heard of, that they thought more of flying to save their lives than of fighting. All those who bore the litter (throne carried by men) of Atahualpa appeared to be principal chiefs. They were all killed, as well as those who were carried in the other litters and hammocks....” --Excerpt from Capture of an Inca King by Francisco Pizarro
What is the historical context for the development described in the document above?