This contribution offers an updated and commented edition of one of the most discussed treatises in feudal law, transmitted by only one witness (Parma, Biblioteca Palatina, Parm. 1227) and whose authorship is still largely hypothetical. Textual and structural analyses of this tradition, compared with MS Wien, Österreichische Nationalbibliothek, 2094 and Baldus de Ubaldis’s Lectura Feudorum, aim at proving that the author might be Iacobus Aurelianus, alias Jacques d’Orleans, a French lawyer probably educated in Italy...