Lord George Hamilton was created Earl of Orkney in 1696. He married Elizabeth Villiers and was succeeded by his daughter Anne (died 1756), the wife of William O'Brien, 4th Earl of Inchiquin. Their daughter Mary (died 1791) became Countess of Orkney. She was succeeded in the title by her daughter Mary (1755-1831) who married Thomas Fitzmaurice (1742-1793), son of John Petty, Earl of Shelburne, and was succeeded in the title by her grandson, Thomas John Hamilton Fitzmaurice (1803-1877). In the mid 19th century the Earl of Orkney held an estate in county Tipperary in the baronies of Eliogarty (parishes of Drom, Inch and Rahelty) and Ikerrin (Bourney and Templeree). The county Tipperary estate amounted to 7,877 acres in the 1870s. The Earl of Orkney also owned 1,642 acres in county Kerry and 1,438 acres in Queen's County (Laois). The Earl of Orkney held over a thousand acres of untenanted land in the Thurles area in 1906.
- Pedigree of Earldom of Orkney and its descent in female line from family of Hamilton through O'Brien to Fitzmaurice, 1666 -- 1832. Genealogical Office: Ms.173, p.152 ; National Library of Ireland
Contemporary printed sources
- ''GRIFFITH'S VALUATION OF IRELAND'[Primary Valuation of Tenements]', 1850-1858. : Barony of Ikerrin, 95 (Castleleiny)
- PARLIAMENTARY PAPERS. ''Return of owners of land of one acre and upwards, in the several counties .... in Ireland''. HC 1876, LXXX: 167
- HUSSEY DE BURGH, U. H. ''The Landowners of Ireland. An alphabetical list of the owners of estates of 500 acres or £500 valuation and upwards in Ireland''. Dublin: Hodges, Foster and Figgis, 1878. [available online at www.askaboutireland.ie] : 356
- PARLIAMENTARY PAPERS. ''Return of Untenanted Lands in Rural Districts, Distinguishing Demesnes on Which There is a Mansion...'', HC 1906, c, 177: 280-281