said to have begun. The two most important people in this process were an Italian lawyer-monk called Gratian (fl. c. 1140), and Peter Lombard (1090–1160), another Italian who migrated to Paris and died there as its bishop. Gratian wrote what he called a ‘concordance of discordant canons’ but which we now know as the Decretum. His work was soon supplemented by a large number of papal decretals, which were subsequently collected and put in some kind of order by different popes—Gregory X (1234), Boniface