Gregory was a remarkably skillful and learned lawyer. He caused to be prepared "Nova Compilatio decretalium", which was promulgated in numerous copies in 1234 (first printed at Mainz in 1473). This "New Compilation of Decretals" was the culmination of a long process of systematising the mass of pronouncements that had accumulated since the Early Middle Ages, a process that had been under way since the first half of the 12th century and had come to fruition in the "Decretum", compiled and edited by the papally commissioned legist Gratian and published in 1140. The supplement completed the work, which provided the foundation for papal legal theory.