Illiterate popes

Several popes are regarded by historians as illiterate, including:

Pope Zephyrinus (199–217) — The Refutation of All Heresies^[1] includes the observation that "Pope Zephyrinus was illiterate."^[2]
Pope Adrian IV (1154–1159) — George Washington Dean writes: "Adrian IV., the only English Pope, had been an illiterate servant in a monastery at Avignon."^[3]
Pope Celestine V (1294) — The Lanercost Chronicle records: "On the commemoration day of S. Paul [June 30], Celestinus the Fifth was created Pope, who, albeit illiterate, was the priest and confessor of his predecessor."^[4]

Wrongly regarded as illiterate

Ludwig von Pastor has shown that Pope Julius II (1503–1513) was not illiterate, although he is poetically referred to as such by Desiderius Erasmus.^[5]^[6]

^ Refutation of All Heresies, collected in Emmanuel Miller (1851). Origenis Philosophumena. p. 284.
^ Christopher Wordsworth (1887). Church History. Vol. 1. p. 290.
^ George Washington Dean (1890). Lectures on the Evidences of Revealed Religion. New York: James Pott & Co. p. 459.
^ Herbert Maxwell (1913). The Chronicle of Lanercost, 1272–1346: Translated, with Notes. Glasgow: University Press. p. 107.{{cite book}}: CS1 maint: numeric names: authors list (link)
^ Association Amici Thomae Mori. 1971. Moreana. p. 103.
^ Philip C. Dust. 1987. Three Renaissance Pacifists: Essays in the Theories of Erasmus. p. 129.