Innocent IV studied Law at Bologna University, was pope from 1243 to 1254, and was still revising the present work until he died. It is a commentary on one of the most important medieval collections of Canon Law, drawn up at the order of his predecessor, Gregory IX. The style of script and decoration show that this manuscript was written and illuminated in Italy (probably Bologna), but an inscription on the first page states that the book belonged in the abbot's study, and a similar inscription in another British Library manuscript (Royal MS. 8 G.i) suggests that this refers to the abbot of St. Albans. This initial 'D' marks the start of Book 4 of the work, which covers laws relating to marriage. In the margin next to the rubric is a 'pecia' note: academic texts such as this were rented out to scribes in pieces ('pecia'), allowing many scribes to be copying different parts of an exemplar simultaneously. In order to keep track of which piece was needed next, scribes commonly made marginal notes such as this.