Holy Knighthood is a Lovian historical novel by Percival E. Galahad, and the name also refers to the total trilogy of novels by that name. The novel Holy Knighthood was written in 1974-1975 and released in 1975. The novel had a sequel in 1976 Holy Knighthood: Return to Hywel. Commercially not very successful, both novels were re-released in the mid-1990s when Galahad had broken through. They were released under the names The Holy Knighthood and The Holy Knighthood II. In 1998, a third novel in the series was written.