Blood Oath is the third book in the series of original science fiction novels based on the Emmy Award-winning series Babylon 5 created by J. Michael Straczynski. The book was written by John Vornholt.

          The book focuses on G’Kar and his conflict with the family of Du’Rog. This conflict first appeared in the television series in the episode "The Parliament of Dreams", where Du’Rog hires an assassin from the Thenta Makur to kill G’Kar because Du’Rog knows G’Kar had a hand in framing him for war crimes, but the assassin fails to kill G’Kar. In the novel, Du’Rog’s daughter Mi’Ra sends G’Kar a message that she has sworn a Skon’Kar. Between the episode "The Pariliament of Dreams" and this message from Mi’Ra, there was another attempt on G’Kar’s life by assassins hired by Du’Rog’s family. This second attempt is mentioned in the novel when G’Kar has recurring nightmares about the attempt.