Reliquary containing a saint's hand bones

The veneration of relics in both the East and the West was early connected with the cult of martyrs and later expanded to include the remaining body of Saints. After the fourth century relics of saints were often transferred from typical suburban burial sites to the sites of the urban churches erected in the centuries after the conversion of Constantine. It became the custom in the West to entomb relics in every altar, and the ritual kissing of the altar by the celebrant before mass was a gesture of veneration of these relics. The veneration of relics in the East was comparatively limited due to infrequent canonization of saints and the use of icons. In the medieval West, on the other hand, the cult of relics flourished, especially in the era of crusades when many relics both genuine and false were sent to the West from Palestine and surrounding areas. Augustine of Hippo and Thomas Aquinas both contributed to a theological rationale for the veneration of relics. They argued that the bodies of the saints were temples of the Holy Spirit and claimed miracles associated with their relics.