First published in 1761, Julie, ou la nouvelle Héloïse has been described as ‘perhaps the biggest best-seller of the century … At least seventy editions were published before 1800 – probably more than for any other novel in the previous history of publishing.’ In the huge corpus of Rousseau's work, it was his one full-length novel. Set in a remote location on the shore of Lake Geneva at the foot of the Swiss Alps, it takes the form of an exchange of letters between a young woman, Julie, and her tutor, St Preux, who would become her lover. The other principal characters engaged in the correspondence are her cousin and confidante Claire, Wolmar, who is destined to become Julie's husband, and an English nobleman, Lord Edward Bomston. The affair is brought to an abrupt halt by Julie's brutal father, the Baron d'Étange, who then marries his unhappy daughter off to his old friend Wolmar. The rest of the novel tells of their apparently harmonious marriage, the exile and return of St Preux, and culminates in a dramatic denouement at Julie's deathbed.

Countless readers recorded their ecstatic, tearful responses in letters to the author. Women and men, aristocrats and commoners, English clergymen, Calvinist pastors like Paul-Claude Moultou and Catholic priests like the Abbé Cahagne, even some sceptical philosophes were overwhelmed by this convoluted narrative of thwarted passion and fragile virtue. They identified intensely with the characters.