Tad Williams 
Shadowmarch 
Shadowmarch Book 1

At the uppermost edge of the northern kingdoms, towers shrouded in mist, lies Southmarch Castle. For hundreds of years it has remained hidden from the affairs of empire. Now its isolation can protect it no more. Southmarch is under siege; from both its neighbours, without, and the more insidious enemies who would destroy it from within. Even further to the north, within the ancient walls of Qul-na-Qar, in a land of silence and gloom, the Twilight People gather to hear Ynnir, the blind king, pronounce the dark fate of human kind. In the south, the Autarch, the god-king who has already conquered an entire continent, now looks to extend his domain once more. It is upon Southmarch that the armies advance, and to its people that darkness will speed.