Modern historians have speculated[6] that this permission was a quid pro quo after Callistus had annulled the marriage to Sibylla of Anjou of William Clito, who was struggling against Henry in Normandy. John, with Peter Pierleone and Gregory of San Angelo, had upheld the annulment.[7] Fulk V of Anjou, Sibylla's father, took this badly, and in late 1124 a stand-off developed.