DECRETISTS. - The rapid dissemination of the *Decretum Gratiani* (v. CORPUS IURIS CANONICI), which quickly came into practical use and was widely employed as a textbook in universities, gave rise to a flourishing school of scholars and commentators. These scholars, developing on the *Decretum* a body of work analogous to that which the Bolognese glossators had conducted on legal norms, enriched canonistic literature with *summae* and commentaries on Gratian’s text. Thus, the term *decretistae* began to be used in a stricter sense to designate these interpreters, the vast majority of whom were ecclesiastics. Moreover, this term is still conventionally used in the history of canonistic literature to denote that period of approximately a century—from about 1140 to 1234—ending with the publication of the Decretals of Gregory IX, after which the *decretalists* (v.) came to the fore. It should be noted, however, that the two terms *decretistae* and *decretalists* ought not to be regarded as mutually exclusive, since the latter did not cease to gloss the *Decretum*, nor did they constitute a distinct school from that of the *decretistae*. Furthermore, the distinction between *decretistae* and *decretalists* is untenable for canonists who wrote on both the *Decretum Gratiani* and the Decretals.
The initiator of the exegesis of the *Decretum* was Paucapalea, a disciple of Gratian himself, who also authored certain interpolations to his master’s text, known perhaps from his name as *paleae*. Among the glossators were also Albert (later Pope Gregory VIII), Rufinus, Johannes Faventinus, Stephanus Tornacensis, Johannes Teutonicus (author of the *Glossa ordinaria* to the *Decretum*), and his reviser Bartholomew of Brescia. Authors of *summae* included, in addition to some of the same glossators, Rolandus Bandinelli (later Pope Alexander III), Simon of Bisignano, Johannes Bassianus, Ognibene, and, among the most notable, Uguccio of Pisa. With the advent of the *decretalist* period, the *Decretum* continued to be taught in universities and elaborated by scholars; noteworthy in this regard are the *Breviarium Decretorum* of the Portuguese Johannes de Deo and the works of Principius and Guido of Baisio.