Fascinating, especially the first half or so. This is both history and historical artifact, as it was written by a Conquistador only a short time after the conquest. De Leon is often surprisingly even-handed and sympathetic toward the Incas, for his time, and his account of the political intrigues among both Spaniards and Incas is detailed and revealing. I found the second half, after the conquest was more or less complete and various sorts of infighting were going on, to be pretty heavy going. Still, well worth reading.