Many scholars have pointed out that it is not likely that Gratian wrote the Decretum in one giant sweep. In this chapter, I want to demonstrate that the work was produced in two steps. A first effort produced a shorter text which I call the first recension. This text was later expanded to form the text that is generally known (from most medieval manuscripts and all modern editions), which I call the second recension. These terms are, admittedly, not always practical to use, particularly not when referring to the author of either recension. In the interests of simplicity and clarity, I have therefore chosen to call the author of the first recension Gratian 1 and the author of the second recension Gratian 2. These labels are not intended to suggest that Gratian 1 and Gratian 2 could not have been the same person.

The first recension is preserved in the original text of the three manuscripts Bc Fd P and in the fragment Pfr. Aa contains the same text with interpolations from the second recension in the main section of its two volumes. The second recension is known (in slightly varying forms) from some six hundred other manuscripts and in numerous modern editions. The second recension contains 3,945 canons (including the paleae) in the editions.