In general, Philip II of Spain has not fared well at the hands of historians: he is often represented as a somber, Machiavellian figure, the famed ""black spider"" working night and day to expand the Spanish Empire and to reimpose Catholicism on a European continent split by the Reformation. Although there is some truth to this portrait of Philip, Geoffrey Parker's biographical study attempts to reveal the other elements in the complex character of ""the most potent man in Christendom."" Parker, author of The Army of Flanders and other works, is successful largely because he has been able to systematically go through the Altamira papers, a collection of about five thousand letters and documents in Philip's own hand. From these he resurrects a much more human Philip: the son of the Emperor Charles V striving to live up to his father's example of diplomacy and conquest; a man with as many human weaknesses and affections as most others, but gradually forced to bury all under an iron discipline and self-control; the King who encouraged the Inquisition and enjoyed a good auto-da-fÃ‰, all because of his deep and sincere religious faith; and, most importantly, the originator of a vast centralized administration that brought all parts of Spain's enormous empire under Philip's personal authority. It was this last, surprisingly modern bureaucratic revolution that allowed Philip to accomplish the ""taming of America,"" which, in terms of the distances and modes of travel involved, was his most impressive achievement. Parker makes a good case when he dismisses the conclusion of many other historians that Philip was essentially a weak person: as he points out, the private papers of the most charismatic of modern leaders reveal that indecision, self-doubt, and crippling infirmities are no strangers to strong rulers. Rather, Philip's failing was that of ""a man of rigid principle with supreme power"" and when his policies were unsuccessful, as in the Netherlands or against England, it was largely because his principles did not allow him to change his policies until it was too late. Perhaps most satisfying of all are the glimpses that Parker is able to give of Philip away from the world stage--of the lover of books, the indefatigable hunter, and the incurable collector of art who loved Titian but never appreciated the Spanish genius of El Greco.