The Expositio in Apocalypsim by Alexander Minorita (also known as Alexander of Bremen, d. 1271) is the earliest complete mendicant Apocalypse commentary. It has been noted for its highly chronological interpretation of the path toward the end times and its witness to the early spread of Joachimite texts into central Europe. Our knowledge of the transmission and, crucially, the use of this text has thus far not taken into account thirty-five folios of instruction on spiritual warfare found in one of the Expositio's eight manuscript witnesses: Cambridge, University Library, Mm.5.31 (c. 1270). The edition presented here of this unique addition, which was excluded from the modern critical edition of the Expositio, makes the complete Cambridge version of the Expositio available for the first time. While there has been some debate over the editorship of this version of the commentary — the Benedictine-turned-Franciscan Albert of Stade (d. c. 1260) and Alexander himself have both been suggested — we argue that a further possibility must be considered. Its author may have been a highly educated Benedictine writer, who adapted the commentary with his coreligionists (at least partly) in mind. His goal was not only to extol the importance within the apocalyptic timeline of Benedictine history, but also to promote ascetic values among his readers. Overall, the Cambridge Expositio provides further evidence of the intellectual conversations and cross-pollination of both practices of learning and structures of thought between mendicant, university, and cenobitic cultures in this period. Within this context, apocalyptic thought could find unexpected uses, including galvanizing monks in day-to-day religious practice and progress.