that Adrian had authored a number of works prior to his election. These included a treatise De Conceptione Beatissimae Virginis, a monograph, De Legationae sua and a catechism for the Scandinavian church. Some of his correspondence survives. One such letter, from Hildegarde, exhorts him to crush the Roman commune. Joseph Baird and Radd Ehrman, editors of a collection of Hildegard's letters, note that it was "perhaps unneeded", as Adrian placed the city under Interdict almost immediately. Much of Adrian's correspondence with both Archbishop Theobald and John of Salisbury has also been published in collections of the latter's letters. Adrian's episcopal registry is now lost, although some decretals—formal rulings—survive. These covered such questions as to whether it was possible to restore a priest to his office when he had been responsible for the death of an apprentice, the payment of tithes, and the marriage of the unfree. Adrian's thoughts on tithe payment also made their way into the body of Canon Law, and were, according to Duggan, "recognised by contemporaries as having special significance, and so included in the collections of canon law being assembled at the time". Personality The historian Colin Morris notes that Adrian's character appears contradictory: "Some historians have seen him as tough and inflexible, but others as a relatively mild man" who could be manipulated by those around him. Duggan disputes that he was either a cypher to be manipulated by the cardinals or a prima donna. Rather, she suggests, he was "a man of discipline, who fitted in with the norms and routines already in place...a man of affairs who had no fixed program, but who responded judiciously to the problems brought before his court. Adrian's chamberlain, Boso—who later wrote Adrian's Vita—described the Pope as "mild and kindly in bearing, of high character and learning, famous as a preacher, and renowned for his fine voice". Julius Norwich describes Adrian as being eloquent, able and with "outstanding good looks". The German antiquarian Ferdinand Gregorovius believed that by nature Adrian was "as firm and as unyielding as the granite of his tomb", while Norwich tempers this suggestion, believing that, at least after Benevento, he must have been far more open to the possibilities of change. Duggan wonders whether he deliberately utilised these traits to forward his career. Boso's characterisation, she suggests, "could imply that he was ready to ingratiate himself with the powerful, to make friends and influence