Crónica del Perú

Cieza de León, Pedro de, Crónica del Perú, Madrid: Espasa-Calpe, 1941.

On-line versions.

Wikipedia:

Pedro Cieza de León (Llerena, Spain c.1520 ---Seville, Spain 1554) was a Spanish conquistador and chronicler of Peru. He is known primarily for his history and description of Peru, Crónicas del Perú. He wrote this book in four parts, but only the first was published during his lifetime; the remaining sections were not published until the 19th and 20th centuries.

See also The Discovery and Conquest of Peru, and Crónicas de la Conquista del Perú .