This is easily one of the most beautifully written books I've ever read.
Kay loves his alternative historical fantasy story lines, and while you could question how fantasy this really is, there is no doubt that this is definitely alternative history.
(Loosely) Set in Moorish Spain, it revolves around three characters, each belonging to one of the three major faiths in the land and explores attitudes within and between beliefs, the use of religion, intra-personal relationships and conflicts. Kay clearly loves his history and clearly researches his subjects, and goes into great detail without getting too weighted in boring events. He keeps this book fast, very fast, without sacrificing the soul of the story or the characters in it.