As Thomas Becket's cult flourished throughout Europe following his murder in December 1170 and canonisation in February 1173, numerous churches and hospitals were dedicated to the saint in Normandy. The duchy of Normandy was closely connected both to England, as part of the Anglo-Norman realm (until 1204), and to Becket himself since, according to tradition, his parents were both burgesses of Norman origin, his father Gilbert coming from Rouen and his mother Matilda from Caen. Becket's cult in Normandy has been studied in detail by Raymonde Foreville, Jean Fournee and Ursula Nilgen; a specific aspect of that cult, the leper houses dedicated to Becket in the duchy, is the focus here. These hospitals devoted specifically to the care of leprosy sufferers were religious institutions, a status formalised at the Third Lateran Council in 1179, which decreed that all communities of lepers should have their own church, cemetery and priest. A number of other saints were popular dedicatees of leper houses in Normandy and England, above all St Mary Magdalene, St Giles, St Nicholas, St Lazarus and St Julian. Thomas Becket thus joined a distinguished pantheon of celestial patrons of lepers.

Deserving particular attention in Normandy are the leper house of Mont-aux-Malades outside Rouen (originally dedicated to St James, and re-dedicated to Becket by King Henry II c.1174) and that of St-Thomas at Aizier, located halfway between Rouen and Le Havre, established in the late twelfth century on land belonging to the abbey of Fecamp. Mont-aux-Malades was a wealthy and prestigious Augustinian priory, which was associated with Becket during his lifetime through his friendship with the first prior of the leper house, Nicholas. The community had enjoyed considerable support from Henry II and other members of the Anglo-Norman royal family prior to 1173. St-Thomas at Aizier was a much smaller and less distinguished institution, but nonetheless offered important provision to lepers, as archaeological excavations of its chapel, associated buildings and cemetery have attested.

The miracle collections associated with Becket's shrine at Canterbury reveal that the saint was quickly attributed with healing a wide range of afflictions. Unusually among miracula, these include cases of leprosy.