Written in 1444, this was one of the bestselling books of the fifteenth century, even before its author, Aeneas Sylvius Piccolomini, became Pope Pius II. It is one of the earliest examples of an epistolary novel, full of erotic imagery. The first printed edition was published by Ulrich Zel in Cologne between 1467 and 1470.
The novel is set in Siena, and centers around the love story of Lucretia, a married woman, and Euryalus, one of the men waiting on the Duke of Austria. After an uncertain beginning, in which each is in love but unaware that it is reciprocated, they begin a correspondence, which takes up much of the rest of the novel. Before writing his first love-letter, Euryalus quotes Virgil in defence of his position, Amor vincit omnia et nos cedamus amori (translated: "Love conquers all; let us all yield to love!").
The lovers were identified by some with Kaspar Schlick, the chancellor of Sigismund, Holy Roman Emperor and a daughter of the elder Mariano Sozzini, Aeneas' law teacher at the University of Siena. This equation of characters is no longer accepted.