Умберто I
In "[[The Death of Achilles]]" the hired killer Achimas is mentioned as having been secretly hired by the Italian government to kill an anarchist nicknamed "The Jackal" who plans to kill [[Umberto I of Italy|King Umberto]] - yet Achimas himself bears considerable similarity to the hired killer nicknamed "The Jackal" who plans to kill [[Charles de Gaulle]] in [[Frederick Forsyth]]'s "[[The Day of the Jackal]]".