The abbey of Saint-Étienne de Caen was founded by Duke William II of Normandy in or around 1063. Within a few years of its festive dedication, it was endowed with extensive lands and churches, many of which were located in the ecclesiastical province of Bayeux. These grants played a key role in shaping Saint-Étienne’s relationship with one of the region’s foremost spiritual and political authorities: the cathedral chapter of Bayeux. This article engages with a sizeable corpus of archival sources (many of which are unpublished) in scrutinizing a particularly important rivalry that emerged between the monks and the cathedral canons during the later eleventh and twelfth centuries, involving not only their respective abbots and deacons, but also the bishop of Bayeux, the archbishop of Rouen, the pope and the king of England. Particular attention will be paid to the symbolic dimension of this rivalry and the ways in which conflicts of authority were turned into political ritual and public display.