I, the King is Philip IV of Spain to whom Mrs. Keyes was first attracted via the nun, Sor Maria, his counselor and comforter, and one of the several influential women who monogrammed his life with the letter M (his sister, his second wife, his mistress). In the long introduction (in which her homemaking instinct only betrays her once-- a recipe) she explains the genesis of the book on which she spent considerable time and research in both English and Spanish. If Philip is less romantic than some of her other subjects, and certainly he often seems more dead than alive here, it must be remembered that he was a most ineffectual sort. And if she writes almost as opulently as ever, the period to some extent justifies and neutralizes it. The story begins with Philip's marriage to Isabel of France when she came ""riding into his life and into his heart."" He was ten, and she was twelve, and ""Of course their married life in the literal sense of the word. did not begin then."" (Perhaps Mrs. Keyes' readership needs this kind of reassurance?) Actually when he ascended the throne at 16, the days of ""merrymaking"" were over and Isabel became capably active in the affairs of state, tried again and again and eventually succeeded in giving him a son. Then there was the ""great love of his life""-- the young actress Maria Ines who terminated the liaison after bearing him another son; his visits to Sor Maria (a true mystic with the gift of bilocation (she appeared 500 times before the Indians in New Mexico); and finally after Isabel's death, and after the loss of his only male heir, the aggressive Mariana of Austria..... I, the King was Philip's signature but it's the author's which will be more significant here.