The first papal decree to list forbidden writings was the Decretum Gelasianum, attributed to Pope Gelasius (d. 496). While this list canonized the works of St. Augustine, St. Jerome, and other "orthodox fathers," it also enumerated which Christian writings were to be rejected as apocryphal and which were to be condemned as heretical. This papal decree served as the point of departure for all subsequent Christian censorship.
06314. Gratian (fl. 12th century). Decretum. [Strasbourg]: Heinrich Eggestein, 1472.
Gratian, active 12th century, Joanes, Teutonicus, –1245?, Bartolomeo da Brescia, 1258, and Eggestein, Heinrich, b. ca. 1415, printer., “06314,” Bridwell Library Special Collections Exhibitions, accessed December 3, 2023, https://bridwell.omeka.net/items/show/1946.