The modern view of late medieval writings on the Summa Theologiae has always been shaped by the role it was going to play in early modern and modern times. If the STh is considered Thomas' most important work—one that would soon be used as a standard textbook for university teaching, most notably replacing the Sentences of Peter Lombard—late medieval writings on the STh are viewed as precursors or even as the first evidence of the prominence to come. This perspective has been condensed, in contemporary research, into two assumptions: first, that, at least in some milieus, the replacement of the Sentences by the STh already took place during the 15th century, and second, that this evolution had its starting point in Cologne. From a medieval perspective, both claims are questionable, if not untenable, and this is what the present chapter will argue for. It analyzes the known late medieval writings on the STh within their contemporary context, arguing that none of the surviving medieval writings on the STh is comparable, from a generic perspective, to the theological manuals based on the STh that appear since the 16th century.