See also Norns on Wikipedia, and the disclaimer.

Norns. The fates of Scandinavian or Norse mythology were three maids named Urd, Verdandi and Skuld, meaning past, present and future. They were supposed to sit by the well of Urd, under the world tree in Asgard, and determine the fate of gods and men. There also were lesser norns, all working on the destinies of man.