The three essays that comprise The Impiety of Ahasuerus examine crucial literary influences on English Romantic poet Percy Bysshe Shelley's depiction of the fabled Wandering Jew. Particular attention is paid to Shelley's portrayal of the Wanderer named Ahasuerus in Queen Mab and Hellas. Ahasuerus is a Reformation adaptation of an ancient Christian legend that describes the conversion of a Jewish bystander at Calvary. Percy Shelley encountered types of Ahasuerus in the fictions of Christian Schubart, Matthew Gregory Lewis, and William Godwin. Shelley enrolls Ahasuerus in the service of his own evolving revisionism, as a zealot in Queen Mab and as a sage in Hellas. Though fundamentally different characters in the two poems, Shelley's Ahasuerus espouses in both works the redemptive power of revolutionary ideas.