Matthew Deane came to Ireland in the mid 17th century and purchased lands in county Cork. He was made a baronet in 1709. In 1775 his descendant, Sir Robert Tilson Deane, (created Baron Muskerry in 1781), married Anne, sole heir to her grandfather John Fitzmaurice of Springfield Castle, county Limerick. John Fitzmaurice was a nephew of Thomas Fitzmaurice, 1st Earl of Kerry, ancestor of the Marquis of Lansdowne. Robert Tilson Fitzmaurice Deane, grandson of Robert and Anne, married Elizabeth Geraldine Grogan Morgan of Johnstown Castle, county Wexford and assumed the additional name of Morgan. Their son, Hamilton Matthew Tilson Fitzmaurice Deane-Morgan, succeeded his grandfather as 4th Baron Muskerry in 1868. In his entry for the parish of Mourneabbey, Lewis refers to the "late Lord Muskerry" (1st Baron) having built "a splendid mansion in the vicinity on which he is said to have expended upwards of £30,000; but before it was inhabited it was taken down and the materials sold''. Beaufort also refers to this mansion which had been dismantled by 1788. It was at Dromore, parish of Kilshannig. Griffith's Valuation records Lord Muskerry holding land in the parishes of Killagholehane, Killeedy and Mahoonagh, barony of Glenquin and Dromcolleher, barony of Connello Upper, county Limerick and in the barony of Orrery and Kilmore, county Cork including parishes of Shandrum and Kilbolane. In July 1864 lands in the baronies of Glenquin, Smallcounty, county Limerick and West Muskerry, county Cork and Maguinihy, county Kerry, the estate of Lord Muskerry and Maria Chinnery were advertised for sale. Maria Chinnery would appear to be the daughter of Sir Broderick Chinnery, baronet, of county Cork. These lands were purchased by Messers. Evans, Nagle and Prin. In the 1870s Lord Muskerry owned 3,161 acres in county Limerick, 742 acres in county Tipperary, 912 acres in county Wexford and 28 acres in county Clare. The rental of Barnagurrane, 242 acres in the barony of Connello Upper, the estate of Eugene Guilford Finnerty, was advertised for sale in November 1881. Lord Muskerry was the tenant and this property adjoined his Springfield Castle demesne.
His wife, Elizabeth Grogan Deane Morgan, was the owner of over 350 acres in county Waterford in the 1870s as well as extensive estates in counties Kilkenny and Wexford.