Pope Pius II wrote a bestselling erotic novel.

You’ve probably never read The Tale of Two Lovers, but a lot of people in the 15th century did. Little did they know that the immensely popular erotic novel’s author, Enea Silvio Piccolomini, would later be known by a different name: Pope Pius II. He assumed the papacy on August 19, 1458, and served until his death almost exactly six years later on August 14 or 15, 1464. Historia de duobus amantibus, as the novel is known in the original Latin, was published in 1444, more than a decade before he became pope, and tells of a sordid affair between a married woman named Lucretia and a man named Euryalus, who serves the duke of Austria; some scholars believe it drew inspiration from the real-life romance between Kaspar Schlick, chancellor of Sigismund, Holy Roman Emperor, and the daughter of Mariano Sozzini, the future pope’s law teacher at Italy’s University of Siena.

Among the first epistolary novels ever written, The Tale of Two Lovers is largely presented as a series of letters between the two main characters. Pius II was a prolific writer in general, having written about history and geography in addition to being made imperial poet laureate by Frederick III of Austria in 1442; much of his poetry was also erotic. Pius II is remembered as a skilled orator, as well, and many of his speeches are still preserved. As pope, he’s best known for attempting to unite Europe against the invading Turks.