Patrick Conolly was a native of County Monaghan, and a descendant of the Ó Conghalaigh clan of Airgíalla.

They had no children, and on Katherine's death in 1752 the estates were inherited by William James Conolly, his nephew by his brother Patrick.

He made his fortune from land transfers, following the confiscations by the Crown of lands belonging to supporters of King James II, in the wake of the Glorious Revolution and the accession of William III and Mary II in 1688–91, known as the "Williamite War in Ireland".

Conolly was the largest individual buyer, in particular buying 3,300 acres in County Meath that had been assigned to the Earl of Albemarle.

Conolly was the most important of the "Undertakers", the managers of Government business in the Irish House of Commons, in the early 18th century.

His name was spelt "Conolly", rather than the more familiar Connolly, deriving ultimately from the Gaelic surname "O Conghaile".

The Conolly residence "Cliff House" on the banks of the River Erne between Belleek, County Fermanagh and Ballyshannon County Donegal was demolished as part of the Erne Hydroelectric scheme, which constructed the Cliff and Cathleen's Fall hydroelectric power stations.