Dante has long been acknowledged as a pervasive presence in Joyce's works, and Mary Reynolds's Joyce and Dante, the fullest study to date, has shown at great length the importance of some key Dantean characters and themes in Joyce's oeuvre. In this essay I shall look at a text which has often been mentioned but whose relevance for Finnegans Wake has never been studied in detail: Dante's De vulgari eloquentia. The De vulgari represents an important force behind the Wake's experimentations with narrative form, its exploration of new notions of character, its integration of such typical and pervasive themes as the battle between father and son or the artist's original creation and his transcendence of the vulgar, the commonplace, the daily – even the excremental – into the eternity of art. This study will thus show, through a reading of HCE's naming, ennobling and fall in FW Ⅰ.2, of Shem's distillation of an ‘indelible ink’ from his own excrement in FW Ⅰ.7, and of HCE's concoction of a new cocktail from the dregs of his customers' glasses in FW Ⅱ.3, how Joyce's narrative, poetic and linguistic masterpiece situates itself at the intersection between a radically modern narrative technique and a mediaeval poet's linguistic theory. According to a mediaeval topos, all secular literature, even the best poetry – i.e. that written in imitation of Virgil – was ‘excrement’; in the words of Robert Hollander, ‘[w]hatever gold one might sift ex sterco Vergilii, excrement was still excrement’.