Most of the Plas Power property was in the parish of Wrexham, especially the townships of Bersham, Esclusham and Minera, but the estate also extended to the counties of Merionethshire (Llanfor, Llanuwchllyn, Trawsfynydd), Flint (Abenbury, Bodfari), Montgomeryshire and Shropshire. Despite its title, the relationship of the founders of the estate - the Power family - with the estate itself was comparatively brief. Sir Henry Power, who was described as 'of Bersham' in 1620, appears to have established the estate. His grandson, John Power, is mentioned in a deed in 1685. By 1699 John had moved to Dover and his descendants later lived at Hill Court in Herefordshire. His lands in Bersham township were sold to William Fownes of Dublin in 1702-1704 for £1,800. In 1732 Mary Myddleton of Croes Newydd, daughter of Sir Richard Myddleton, 3rd Baronet, of Chirk Castle, purchased the estate from the Fownes family. William Lloyd, son of the Rev. Thomas Lloyd, Mary Myddleton's chaplain, inherited the estate when she died in 1747. William Lloyd became a trustee of the Chirk Castle estate under the terms of Mary Myddleton's will. William died in 1793 and was succeeded by his second son, another William, who died without issue in 1816. The estate then passed to William's nephew, Thomas FitzHugh, son of Thomas FitzHugh of Portland Place, Marylebone, London, and Mary, the sister of William Lloyd (junior). The estate eventually passed to Thomas's great-grandson, Lieutenant Colonel G. E. FitzHugh. The FitzHugh family also owned property in Middlesex and Essex. According to the 1873 return of owners of land Thomas Lloyd FitzHugh of Plas Power, Denbighshire, owned 3,362 acres (situated in Denbighshire and Flintshire) which carried an annual rental of £5,573.
Scope and content: Plas Power estate papers, including deeds, 1576-1921, mainly for lands in Denbighshire, 1576-1914, mainly in Wrexham townships, Flintshire, 1702-1899, Merionethshire, 1642-1824, Montgomeryshire, 1719-1747, Cheshire, 1658-1828, Lancashire, 1633-1674, London, 1730-1925, and Shropshire, 1719-1871; estate papers, 1702-1921, including accounts, 1702-1919, rentals, 1702-1910, surveys and valuations, 1820-[c. 1830], maps, [c. 1780]-[c. 1900], sale papers, 1761-1896, tithe papers, 1839-1906, and correspondence, 1727-1921; legal records, 1727-1891; business and industrial papers, 1793-1918, including papers relating to the United Minera Mining Company and its lead mining activities, 1893-1916, papers of the Minera Stone Quarries Ltd, 1894-1918, and royalty accounts received by the estate from collieries in the Wrexham area, 1880-1914 (Coedpoeth, Bersham, Plas Power, Vron, etc.), correspondence, 1892-1914, and plans; and family papers, 1697-1926, including marriage settlements, 1697-1828, probate records and inventories, 1658-1926, correspondence, 1801-, and accounts, 1868-1910. The archive also includes papers relating to the Chirk Castle estate including estate papers, 1675-1681, 1695-1803; legal records, 1684-[c. 1816]; and family papers, 1673-1813, including wills and inventories, 1712-1747, accounts, 1801-1813, and correspondence, 1703-1813; and correspondence and papers of Christopher Goodman, puritan divine, of Chester (c. 1520-1603), 1554-[c. 1591].