Family and estate records of Griffith of Porthamal, Anglesey, and Llanfair, Caernarfonshire, Griffith of Brynodol, Caernarfonshire, and the associated families of Rowlands of Nant, Caernarfonshire, and Wynn of Taltreuddyn, Merionethshire. The estate records include rentals of the Llanfair estate, 1516-1669, the Brynodol estate, 1581-1751, the Cefnamwlch estate, 1630-1717, the Nant estate, 1702-1719, the Taltreuddyn estate, 1744-1848, the Llanfair and Brynodol estate, 1761-1832, and rentals from various other estates, 1615-1816; and deeds of the Porthamal and Llanfair estate, 1435-1673, the Brynodol (and later Llanfair and Brynodol) estate, 1564-1864, and the Taltreuddyn estate, 1664-1751. -- The archive also includes rentals of Crown rents in Anglesey, Caernarfonshire, Denbighshire, Flintshire and Merionethshire, 1558-1798, and ministers' accounts, 1365-1825; Caernarfon borough records, 1545-1783, including rentals of corporation property, lists of burgesses, and notes on the constitution of the borough and the appointment of officers; and a number of literary and historical manuscripts.

Estate and family papers of Owen and Wynne families of Peniarth, Merionethshire, [15 cent.]-[19 cent.], including groups relating to Mostyn of Nant and Mostyn and Williams of Penbedw, Flintshire, to Maurice of Lloran, Denbighshire, and to Corbet of Ynysmaengwyn, Merionethshire, including estate papers, 1630-1870, rentals and accounts; deeds, 1361/2-1963, mainly for Peniarth, Aberllefenni, Penbedw, Drenewydd and Mallwyd estates; legal papers, 1539-1848; industrial papers, 1615-1852; county administration, 1468-1874; and non-family trust papers, 1468-1878, mainly relating to the Ynysymaengwyn estate.

Rhiwlas estate records, [c. 1563], 1609-1888, including deeds, 1609-1888; rentals, 1796-1855; legal papers, [c. 1563], [c. 1632]-1847, including papers relating to a 19th century dispute about diverting the river Meloch; family and personal papers, 1631-1937, including family trust papers relating to the estate of Thomas Jones (d. 1819), rector of Derwen, Montgomeryshire, and brother-in-law of Richard Watkin Price; non-family trust papers relating to the estate of John Lloyd of Wigfair and Hafodunos; and letters, mainly from the first half of the 19th century, mainly to Richard Watkin Price.