In the Plea Rolls of the Exchequer of the Jews, Trinity Term 1277, Adrienne Williams Boyarin finds the case of one Sampson son of Samuel, a Jew of Northampton, arrested for impersonating a Franciscan friar and preaching false Christianity. He was sentenced to walk for three days through the centers of London, Canterbury, Oxford, Lincoln, and Northampton carrying the entrails and flayed skin of a calf and exposing his naked, circumcised body to onlookers. Sampson's crime and sentence, Williams Boyarin argues, suggest that he made a convincing friar—when clothed. Indeed, many English texts of this era struggle with the similarities of Jews and Christians, but especially of Jewish and Christian women. Unlike men, Jewish women did not typically wear specific identifying clothing, nor were they represented as physiognomically distinct. Williams Boyarin observes that both before and after the periods in which art historians note a consistent visual repertoire of villainy and difference around Jewish men, English authors highlight and exploit Jewish women's indistinguishability from Christians. Exploring what she calls a "polemics of sameness," she elucidates an essential part of the rhetoric employed by medieval anti-Jewish materials, which could assimilate the Jew into the Christian and, as a consequence, render the Jewess a dangerous but unseeable enemy or a sign of the always-convertible self.

The Christian Jew and the Unmarked Jewess considers realities and fantasies of indistinguishability. It focuses on how medieval Christians could identify with Jews and even think of themselves as Jewish—positively or negatively, historically or figurally. Williams Boyarin identifies and explores polemics of sameness through a broad range of theological, historical, and literary works from medieval England before turning more specifically to stereotypes of Jewish women and the ways in which rhetorical strategies that blur the line between "saming" and "othering" reveal gendered habits of representation.