Business records and personal papers of Richard Owen, Glan Conway, Denbighshire, [c.1910]-[c.1960], including ledgers, account books and financial papers, index of funerals, 1927-1959; and family papers, [19th cent.]-[20th cent.].

Deeds and documents, 1555-1875, relating to properties in the counties of Pembrokeshire, Anglesey, Montgomeryshire; deeds, 1696-1868, of lands in the parishes of Llanfair Dyffryn Clwyd, Llanelidan, Efenechtyd, and Llanfwrog, Denbighshire; and documents, 1735-1868, relating to the Eyarth Estate, Denbighshire.

Personal papers of Sir John Williams comprising notes, essays, lectures and transcripts by him, [19th century]-[early 20th century]; certificates and testimonials, 1858-1915; cards and letters from the children of King George V and invitation cards to royal functions, 1889-1916; documents relating to his various honours, 1894-1911; photograph and stamp albums, 1849-[early 20th century]; other photographs, [1840s]-1905; press cuttings, [c. 1870]-1926; letters collected by Sir John, 1633-1912; letters to him, 1879-1922, the correspondents including members of the Royal Family; deeds and other documents relating to properties in Llangadog, to Plas Llanstephan and to Harley Street, London, 1790-1918; bibliographical material, [19th century]-[20th century]; medical notebooks and other papers, 1855-1900; diaries of Sir John and Lady Williams, 1872-1925; estate and financial records, 1890-[1926]; papers relating to public affairs, 1870-1911; miscellaneous items collected by Sir John, 1795-[c. 1919]; personal possessions, including University and commemorative medals, insignia, medical equipment, and ceremonial trumpets, 1861-1913; and deeds collected by Sir John Williams, 1546-1869, comprising deeds of the Vaughan family of Llanelli, Carmarthenshire, the Penry family of Swansea, Glamorgan, and the Dalton family of Pembrey, Carmarthenshire, 1545-1677, relating to properties in Llangennech and Pembrey, Carmarthenshire; deeds of John Jones, Ystrad, Carmarthenshire, relating to Llansadwrn, Carmarthenshire, 1632-1793, and the borough of Carmarthen, 1611-1869; Wynn of Gwydir deeds, 1352-1797, relating mostly to Caernarfonshire, Merionethshire and Denbighshire; miscellaneous Welsh deeds, relating mainly to properties in Carmarthenshire and Cardiganshire, 1451-[c. 1840]; and miscellaneous deeds relating to England (mainly Cornwall and Staffordshire), Ireland, and Scotland, 1586-1896.

Manuscripts collected by, and papers of, the Rev. T. Llechid Jones, including personal correspondence, 1883-1943; miscellaneous correspondence, 1826-1907; diaries, 1888-1935; addresses, 1911-1937; miscellaneous notes, 1888-1941; antiquarian notes, 1700-1943, mainly relating to parishes in North Wales; press cuttings, 1890-1934; pedigrees, genealogical material and correspondence of H. R. Hughes, 1867-1920; deeds and documents relating to Llysfaen, Caernarfonshire, and elswhere, 1597-1880; and printed books, with manuscript notes, 1678-1937.

A copy of Donald Parr's thesis, 'The study of the development and present form of agriculture in Denbighshire', prepared for the degree of BA (University of Durham, 1959).

Deeds, documents and plans, 1455-1895, relating to properties in Anglesey, Caernarfonshire, Denbighshire, Merionethshire and Montgomeryshire; including papers of the Poole family, owners of the Caenest and Pencraig estates in Merionethshire and Anglesey; surveys, [c. 1770] of the Caenest and Pencraig estates; and building leases for properties in the port of Amlwch, [late 18th century].

Deeds purchased from W. A. Evans, relating to Denbighshire, Flintshire and Anglesey, 1310-1795.