Estate and family records of the Chirk Castle estate, mainly in Denbighshire, comprising deeds from 1284; manorial records, mainly of the lordship of Chirk and Chirkland, 1322-1853, including receiver's accounts, ministers' accounts, court rolls, etc.; records of the estate's involvement in the coal, iron and lead industries in Denbighshire from 17 cent.; Denbighshire Quarter Sessions records, including order books, 1647-1675, rolls, 1643-1699, and a book of indictments, 1670-1690; Denbighshire militia records, 1602-1797, and related local government records, 1602-1811; business papers of Sir Thomas Myddelton (1550-1631); personal and estate correspondence from c.1600; literary manuscripts, c.1630-1887; and parliamentary election papers for Denbighshire and Denbigh boroughs, 1681-1852, including papers relating to quo warranto proceedings against the mayor and burgeses of Holt, 1739-1743.
Ten designs for stained glass panels, with armorial pedigree of the Myddelton family attributed to A. W. N. Pugin and John Hardman Powell; three hundred and thirty-two volumes relating to the Chirk Castle estates; a collection of miscellaneous volumes and documents relating to the Chirk Castle estates, including an account book of the Nangwrud Slate Quarry, rentals books, account books, volumes relating to the Black Park Colliery, a rabbit account book, and other papers; and an indenture, 1812, relating to Bodlith, Llansilin, part of the Chirk Castle estate were acquired. These remain uncatalogued.
A manuscript account book for Sir Richard Myddelton's properties at Chirk Castle and Soho Square, London, 1686-1700 and 1748-1752.
A manuscript Steward's letter-book relating to Chirk Castle, 183501838.
Myddelton family, of Gwaenynog, Denbigh, Chirk and Ruthin, Denbighshire, London, and Essex