Honorius, along with John of Tynemouth and Simon of Southwell, and perhaps Nicholas de Aquila, are the first known teachers of canon law at Oxford.
[5] While still involved in proving his case for holding the archdeaconry, he left Geoffrey's service and by 1202 at the latest was serving Hubert Walter, the Archbishop of Canterbury, who gave him two benefices.
He was also employed by Walter at Rome, where he served as the archbishop's proctor at the Curia in a case involving the abbot of Thorney Abbey.
[8] As a canonist, Honorius was the author of a treatise entitled Summa decretalium quaestionum, which exists in six[8] or seven manuscripts.
[3] The work is divided into three parts covering procedures, laws relating to consecration and church offices, and marriage.