The Persian Empire was the world's dominant geo-political force from the later sixth century to its conquest by Alexander in the 330s BCE. Much of the empire's territory was conquered by its founder, Cyrus the Great. King of the World provides the most cohesive and readable portrait of the ruler, whose immense impact on ancient civilization is not fully appreciated. The contrast between this archaeological exposition and the narrative paraphrases of the more literary sources suggests that it may be of more interest to Classics teachers than learners; but those teachers could probably find ways to make use of it.