Kay writes historical fantasy. This isn't a thing I knew the first couple books of his I read. I finished Tiganna without every making the connection that it was a fictionalized Italy that was being portrayed, and I didn't care. The book was phenomenal, and knowing that it was historical fantasy would probably have prevented me from reading it. It smacks of Alternate History, which I typical don't enjoy at all. Clearly, I am a fool, and only luck and ignorance saved me in this case. I am a learning animal, however, and capable of accepting that Kay is a gentleman of phenomenal talent who I should in no way discount for arbitrary reasons. And so I read The Lions of Al-Rassan, and was richly rewarded for my open-minded, cosmopolitan, and generous nature. Lions takes place in a Kay-ian fictionalized version of medieval Europe, circa the 11th century and focusing, in part, on the life of an El Cid analogue and the conflict between Muslims, Jews, and Christians. If you are a student of history, you will see many historical parallels here. Otherwise, don't sweat it.
This is, in many ways, a book about a war that everyone knows is coming. One group, previously ascendant and militarily dominant has fallen into decline. Another group, largely exiled from their historical holdings prepares to return in force now that their centuries-old foe has weakened. A third group, historically persecuted by both sides has finally found a sort of safety in obscurity, and (correctly) predicts that the coming war will crush them between both sides. At the center of the story are three unlikely companions from all sides of the conflict who forge a strange but powerful friendship... knowing all the while that it is likely doomed.
The characters are well written, brightly characterized and interesting. They do tend towards being super-human, but then, they are extraordinary people. Their relationships are compelling, engrossing, tragic, and often gut-wrenching. The plot is tight and moves this pretty weighty volume along with ease. Overall, Lions is excellently written and I highly recommend it. My only real complaint, and I'll be the first to admit that it's pretty nit-picky, is that Kay uses one particular literary device far too often. While effective in moderation, there are only so many times that I'm willing to deal with the whole "let's tell you someone dies and then spend 10 pages teasing you about how you don't know who it is" before it starts to get on my nerves. Honestly, after the first time it actually detracted from the drama of the moment because I was pissed that he was "pulling that crap again".
Final balance: Lions is Kay at or near his very best, and I highly recommend it. It's emotionally compelling and deals with some pretty interesting Big Issues without ever getting bogged down in them.