Mother of Kings is a historical novel by American writer Poul Anderson, first published in 2001 by Tor Books.

The book has considerable fantasy elements, taking place in a universe in which magic exists.

The plot accepts the version that in her teens Gunnhild learned magic from two Finnish wizards, and became an accomplished witch – including the ability to shape-shift and turn herself into a bird at will – and that she often used her magical abilities maliciously, in order to hurt her and her husband's enemies.

Eirik Bloodaxe had a bad reputation in his lifetime and later, being considered especially violent and aggressive even by the standards of the Viking Age.

In his own version, Anderson describes several morally questionable acts by Gunnhild – but still, carefully notes her own point of view and her reasons to do as she did.