Drumlane (Irish: Droim Leathan, meaning 'The Broad Ridge') is a townland situated near the village of Milltown, area 85.76 hectares (211.93 acres), in County Cavan, Ireland.

Significant also then that Drumlane was once a town on the border line between east and west Breifne, also burial grounds for O'Rourke and O'Reilly clan chiefs.

Then in 1436 the Pope appointed Patrick Ó Faircheallaigh as Canon (Coarb) of St. Mary's Drumlane priory then a dependency under the Abbey of Kells.

[4] It was around this time that the Pope agreed to a request from Bishop McBrady to build a cathedral church for a Kilmore diocese within east Breifne.

[5] When Hugh O'Reilly died in 1583, it was disclosed that he had only ever paid one half of one years rent on all of his leased properties, leading to forfeiture of the Cavan monastic lands and sold as the crown administrators saw fit.

Drumlane was Cavan's richest ecclesiastical foundation consisting 32 polls (around 800 acres of pasture and arable land).

The original monastic structures at Drumlane were built from wood gathered from the nearby oak forests, having deteriorated over centuries of weather and raids from Vikings and rival clans.

Other building works probably came from donations paid by prominent local farmers and pilgrims to view St. Mogues relics at Drumlane.

There is evidence of various stages of construction and significant modifications over the centuries, from the late twelfth and early thirteenth century became a 'Transition' period, when late stages of Hiberno Romanesque style architecture gave way to the English Gothic styles being introduced to church construction all around the country.

The windows and doorways in the south and north walls come from a later period using medieval arched forms, while some are hooded (original English style) Gothic design which became popular from the early thirteenth century.

During the summer of 2021, a Topography and Geophysical survey was carried out of the lesser known St Mary Priory site by the local Drumlane History and Heritage Group, together with a large gathering of enthusiastic community helpers.

Without trench digging, it is therefore reasonable to conjecture that this was in fact once a substantial range of ecclesiastical buildings, as described in historic documentation, including a chapel and accommodation for Augustinian canons from the late medieval period.