Hugh Thomas is a worthy successor to John Hemming in explaining the Spanish Empire of the 1500's. Taking up from his book on the conquest of Mexico, Thomas turns to the later reign of Charles V, and the problems he had to confront in dealing with his American possessions. Their moments both of humour and of horror in the narrative. The efforts to create a more humane empire, and the obstacles to doing so, are exposed to the reader. The immense picture has not been so well displayed before. ( )