Osbert served as a royal judge under three English kings: Henry II,
Richard I, and
John. the historian
Barbara Dodwell said of him that "of all the justices his knowledge of East Anglian disputes was probably the greatest". It appears that Osbert's royal service was confined to judicial matters, as no other evidence of any other offices has surfaced. The treatise
Tractatus of Glanvill, which is traditionally attributed to Osbert's uncle Ranulf de Glanvill, and to which Osbert himself may have contributed, names only seven judges, including Osbert. He was one of a group of royal justices that included
Simon of Pattishall,
Ralph Foliot,
Richard Barre,
William de Warenne, and
Richard Herriard, used by Hubert Walter, the
Justiciar of England during Richard's reign, and chosen for their ability rather than any familial ties. This group replaced the previous system of using mostly local men, and represent the first signs of a professional judiciary. In 1194 Osbert was one of the collectors of the
carucage in eastern England, along with Barre and de Warrene. ==Later life and death==