See Landed Estates Database
The Economist Magazine had a recent piece on Sir William Petty:
Every now and then a true genius appears. Petty qualifies. The view of him in Ireland is coloured by his role in acquiring the Kenmare Estate then named the Landsdowne Estate;
However as the piece points out he is the inventor on National Accounts among other things a truly amazing polymath.
In the Paddy O’Keeffe (Bantry Antiquarian) papers now in the Cork Archives there is a reference to him prohibiting non-Protestants from working in his Berehaven mines.
Bowood House Family Tree Landsdowne:
Dereen, Co. Kerry: