A monastery was founded on the site c. AD 545 by Diarmait mac Siabairr, a member of the local Uí Bairrche ruling family.

[2] The monastery was plundered by Diarmait mac Máel na mBó in 1041; the dairthech (oak prayer house) was demolished, a hundred people taken away as slaves and 700 cattle also seized.

This attack was a retaliation against the burning of Ferns by Murchadh mac Dunlaing and the murder of Domnall Remar (Donal the Fat, Diarmait's brother).

None of this original monastery survives; a round tower once stood there but was torn down by the landowner in 1704.

[4] The church, built in the 12th century AD (probably in 1150–60),[5] is built of rubble masonry with dressed quoins and is particularly noted for its Romanesque archway, zoomorphic carvings and Scandinavian-influenced knotwork.