[2] He served as Dean of Down from 1831 to 1839 before being elevated to the episcopacy as Bishop of Tuam, Killala and Achonry in 1839, a position he held until his death in 1866.

He moved to live on a private estate at Tourmakeady, where he evicted many Catholic families for not sending their children to the Protestant school.

In 1852 Plunket increased his holdings to over 10,000 acres, and his 203 tenants were recorded as paying an annual rent of 2000 pounds.

Plunket was a champion of the “second reformation”, an evangelical campaign which ran from the 1820’s to the 1860’s.

On 26 October 1819, Plunket married Louisa-Jane (1798–1893),[3] 2nd daughter of John William Foster of Fanevalley, County Louth.