204 Proceedings of the Royal Irish Academy. 
is there. The south wall of the choir of the 1278 church is the 
southern curtain wall. The entrance to the northern fortress through 
the curtain wall still exists under the fifteenth century tower, and the 
quoin of the eastern end of the thirteenth century church stands in 
the middle of the western tower of the fortress. The question is—Who 
built the fortress? It cannot have been built subsequently to 1278 or 
1433. The Norman invasion (Henry II.) was in 1171. Can it be 
possible that so formidable a building, surrounded by a moat, earth- 
works, etc., could have been built and also razed within a century, 
without a note of its existence being extant? Discarding this idea as 
most improbable, we must look backwards to the time of Brian Borou, 
1002, and come to the conclusion that the fortress of which we now 
find the remains in connexion with Quin Abbey was erected prior to 
the Norman Invasion, thus indicating a period of civilization anterior 
to 1711, in which military requirements were well known, and stone 
castles of an important character built. 
