History of the Incas is a product of the collaboration of the author's research and interviews and the natives' cooperation. The author made it clear in the first part of the book that the contents have been verified and are considered authentic by the natives. Although the book discusses the mythical origin, movement and settlement, succession of rulers, and the wars of the Incas, its goal is to prove to the then King of Spain, Philip II, that the lands occupied by the Incas belong to the King and not to the natives. This will be explained in the later part of the book after describing the downfall of the last Inca ruler.
The first few chapters describe the peopling of the continents after the Flood. The descendants of Atlas divided the lands amongst themselves. This part may be irrelevant but I don't suggest skipping this. There is however an account of the mythical origin of the land of the Incas and its people that was provided by the native correspondents.
Next is the description of the division of the provinces and the first rulers. The rest of the book is a chronological account of the rulers and their deeds. The native terms used in the books are explained. The author also included his opinions of the rulers and their "barbaric ways."
This volume has plenty of information if the reader ignores the colorful comments of de Gamboa and the first five chapters. Keep in mind however that this was intended for a particular audience.
The accounts of the rulers are detailed and written very well. It almost reads like a novel. The myths are limited only to the chapters describing Viracocha and the origins of the Incas of Cuzco.
Rating: 7 out of 10
*The copy I have is a translation of Sir Clements Markham, KCB