Following the implementation in Ireland of the dissolution of the monasteries in 1542, it was acquired by the Kingsland branch of the Barnewall family, later Viscount Barnewall.
His father, a close associate of Thomas Cromwell, was a key figure in the Irish administration between about 1535 and 1542: initially opposed to the Dissolution of the Monasteries, he turned in time to profit handsomely, acquiring Grace Dieu in Dublin and Knocktopher in Kilkenny.
It was created on 19 February 1777 for Sir Hercules Langrishe, who represented Knocktopher in the Irish House of Commons.