Book excerpt: This is a portrait of Diego Velázquez, from his arrival at the court of King Philip IV of Spain in May 1622, to his death 38 years and several hundred paintings later. It is a portrait of a relationship that is not quite a friendship, between a king and his subject and between an artist and his subject. It is a portrait of a ruler, always on duty, and increasingly burdened by a life of public expectation and repeated private grief. And it is a portrait of a court collapsing under the weight of its own excess.