Long time ago, when the world was created, the ancient mights gave it a Lord over the death souls, who had to controll over the might of them. He was called the Lich King.
But the Lich King used this great might for his own thinkings. He killed the ancient mights and let the dead souls destroy their own kingdom.
The people of the world fighted their own fathers, who wanted to steal their souls. The Lich King noticed that the might of the dead alone wasnt enough, so the living people destroyed his dead army. The Lich King escaped to the frozen grounds of Caerdia, and built his army.
He discovered that the dead souls were much more mighty when they were buffed with the essences of frost.
Now, he is rising again, and his dead soul army is following him to every conquest...