[2] Cantilupe at first followed in his father's footsteps, entering the service of the Exchequer and acting as an itinerant Justice in the early years of Henry III.

At first a court favorite, Cantilupe came at length to the belief that the evils of the time arose from the unprincipled alliance of crown and papacy.

[citation needed] Cantilupe raised his voice against papal demands for money, and after the death of Grosseteste in 1253 was the chief spokesman of the nationalist clergy.

During Montfort's rule Cantilupe appeared only as a mediating influence; in the triumvirate of electors who controlled the administration, the clergy were represented by the Bishop of Chichester.

[3] He was respected by all parties, and, though far inferior in versatility and force of will to Grosseteste, fully merits the admiration which his moral character inspired.