The novelist John Buchan wrote Gordon was so "unlike other men that he readily acquired a spiritual ascendency over all who knew him well and many who did not...", but at the same time Gordon had a "dualism", in that "the impression of single-heartedness was an illusion, for all his life his soul was the stage of conflict". Gordon's attempt to have his former archenemy Zobeir, the "King of the Slavers" whom he had hunted for years and whose son he had executed installed as the new Sultan of the Sudan appalled Gladstone and offended his former admirers in the Anti-Slavery Society.