The Bath estate comprised roughly the eastern half of the barony of Farney, Co. Monaghan, almost the whole of which had been granted by Queen Elizabeth to Walter Deverux, 1st Earl of Essex, in 1575. In 1646, with the death of his grandson, the third Earl of Essex, the estate fell into co-heiress-ship between the Thynne family, Viscounts Weymouth and subsequently Marquesses of Bath, and the Shirley family (whose papers are separately noticed and bear the PRONI reference D3531). The Brownlow family came into possession, by 1690, of a large perpetuity-leasehold part of the estate.