Abstract Bishop Bateman’s assertion of his authority over the exempt abbey of Bury St Edmunds in 1345 brought him into conflict with a house closely linked to both papacy and Crown, and came at a time of Anglo-papal tensions. Bateman was no anti-papalist but, as a legal rigorist, wanted to satisfy himself about Bury’s claims to exemption and restrain its monks’ extra-mural misbehaviour. He had some basis for this in canon law, but the ensuing lawsuit at the papal curia seemed to be going against him until swept aside by a writ of prohibition. The monastery looked to the Crown as its chief protector, and the English courts asserted royal rights aggressively. They found Bateman and his commissaries in contempt for breaching the prohibition and for asserting that only the pope could confer exemption; the abbey’s papal privileges were only confirmations of royal charters. They confiscated Bateman’s temporalities and imposed massive fines, and the pope was powerless to intervene. This amounted to a repudiation of 250 years of canon law, harking back to the eleventh-century Eigenkirche. But Edward III needed Bateman as a diplomat, and imposed a compromise under which both sides withdrew their suits and he pardoned the bishop. As Anglo-papal relations settled after 1350, the Crown let canon law stand and did not enforce the doctrines developed in this case. Edward was content with bringing his bishops to heel, and the two systems resumed their normal co-operation. Still, the courts had set a new precedent for royal control.