Gratian's Decretum had been a standard work for nearly three centuries before the invention of printing, and hundreds of copies had been laboriously made in manuscript to serve the needs of lawyers, scholars, and all who were concerned with canon law. Because of it's popularity, the Decretum was among the first books issued by Europe's earliest printing presses. It was printed for the first time in the city of Strassburg by Heinrich Eggestein in 1471. That edition must have sold well, for Eggestein issued the same text again the following year. The University of Michigan Law Library copy is of this second printing, dated 1472.
C. Kenneth Boyce,
A Close Look at "A Cradle Book",
Law Quadrangle (formerly Law Quad Notes)
Available at: https://repository.law.umich.edu/lqnotes/vol17/iss1/5