In 1152 A.D., at the Synod of Kells, parish boundaries were established and it was after this synod that the boundaries of Tullylish and Donacloney would have been defined. Parish churches were erected to replace the old monastic settlements, which were destroyed by the piratical raids of the Vikings. Research done by the late Monsignor Christopher Murray shows that in the case of Donacloney, among the names of clergy associated with the parish in post-Norman and pre-Reformation times, is to be found an Archdeacon named Andrew who occupied that office in 1244 and who immediately afterwards became bishop of the diocese in 1244. While Archdeacon, he was in charge of Donacloney.

We have to move in time to 1406 before we find documentary evidence of other priests.
1406-1414: Thomas McStay; 1414: Adam McGinn; 1434: Patrick McEvoy; 1451-1456: Patrick McStay; 1461-1479: John O'Shiel; 1492: Donat McGinn; 1526-1529; Arthur McGinn.
In the Register of Primate Cromer, under the date 1526, we read "Tullylish Rec. Tolachlys vacant by the death of Eugenius Ysuggl (O'Shiel) united to the Archdeaconry of Dromore on account of the limited income of Archdeaconry". The next Archdeacon to Eugenius O'Shiel was Arthur McGinn (1526-1529). In the Register of Primate Dowdall the following are valuations payable to him when he made his provincial visitations: "Ecclesia de Tullaghlyss - 2 marc; Taxatio Omnium Beneficiorium, Diocesis Drumorensis Anne - 1546; Rector de Tulaglys - 3 marc; Vicarius it idem - 3 marc.' There appears to be no other documentary reference to the early history of Tullylish Parish.