The history of St Saviour's Priory remains very unclear. According to the Official Guide, it is said to have been founded by St Laurence O'Toole in 1162, but the author(s) provide no supporting evidence. The Vita of St Laurence states that while he was abbot of Glendalough (1154–62), the saint showed a great zeal for church building, and on this basis Francoise Henry attributed the foundation of the priory to him. The style of the carving lends support to this idea, the analogies with Baltinglass (founded 1148), suggesting a date in the 1150s for the sculpture. The only caveat is the keystone of the first order of the chancel arch, which has a filleted roll, a feature which is not to be expected in Ireland as early as the 1150s (but see also Killeshin for an early use of fillets). The fact that St Saviour's followed the Arrouasian Rule strengthens the connection with Laurence O'Toole, who introduced this branch of the Augustinian canons to Holy Trinity Dublin, soon after he became Archbishop of Dublin in 1162.