My article focuses on the Franco-Italian poem Attila Flagellum Dei , composed by Nicolò da Càsola, an Italian notary, in the second half of the XIV century for the Estensi in Ferrara, in order to celebrate the heroic origins of the family: actually, it is the first encomiastic poem dedicated to them, before the major works by Boiardo and Ariosto. The poem is witnessed by a single manuscript (divided into two tomes), supposedly in the hand of the author himself. My study provides a new biographic profile of Nicolò and his family, also through an overview of some archival documents from the Archivio di Stato in Bologna. The article also presents a brief summary of the narration, and outlines the principal characters, the positive ones ( Forest and Gilius in particular) as well as the negative ones (Attila), seen as prototypes alluding to other fictional or historical figures ( Forest = Hector of Troy; Attila = the entire Visconti’s family). At last, my paper offers a sample (the proem) of the critical and commented edition I am working at. The text is preceded by an analysis that illustrates its peculiar linguistic features, with a particular regard on the rhymes: indeed, far from being representative of the generic class of Franco-italian works composed by Italo-Romance authors, the poem Attila Flagellum Dei shows a combination of hypercharacterized French and Italo-Romance dialects of Northern Italy.