Papers, 1634-1928, mostly deriving from and relating to the legal practice of Henry Rumsey Williams, comprising draft conveyances, abstracts of title, letters, accounts and miscellaneous papers of clients, including the estate of Wynn of Glynllifon, 1719-1840, the Griffiths family of Caernarfon and Amwlch, 1726-[1830s], Jared Jackson, 1760-1836, Plasgwyn estate, 1761-1846, Cefn Cwmwd estate, 1763-1828, Coed Helen estate, 1770-1838, Trergo estate, 1771-1832, Parry family, 1773-1788, Peniarth estate, 1773-1830, Orielton estate, 1774-1814, Bodior estate, 1778-1837, Faenol estate, 1778-1840, Arnold Robinson Burrowes, 1785-1837, Grindley family, [c. 1786]-1842, Morgan family, 1787-1839, Treiorwerth estate, 1787-1844, Evan Pritchard, 1788-1813, John Price, 1790-1844 Caerhun estate, 1791-1834, W. A. Madocks, 1799-1824, Nancall estate, 1802-1837, Morris Griffith, 1804-1832, Edward Griffith Roberts, 1805-1827, William Humphrey, 1805-1833, Plas Llanfair estate, 1805-1837, Baily Williams family, 1806-1838, Richard Garnons, 1809-1837, Cefn Hengwrt estate, 1810-1815, George Bettiss, 1810-1831, William Edwards, 1811-1836, Penrhyn estate, 1811-1837, Wyatt family, 1813-1835, Gelli Goch estate, 1815-1831, Anna Maria Wynne, 1816-1833, Robert Thomas, 1818-1839, Roberts family, 1818-1840, Bodegroes estate, 1819-1836, Hughes, Brydges and Granville, bankers, 1819-1840, Vickers family, 1820-1833, Boston estate, 1820-1839, Owen Griffith, 1822-1846, George Holmes Jackson, 1823-1841, the Rev. Hugh Hughes Wynne, 1831-1848, John Rowlands, 1832-1841, and Edward Hosier Williams, 1833, in Caernarfonshire, Anglesey, Denbighshire, and Merionethshire; legal correspondence, 1790-1848, probate records, 1727-1871, and papers relating to civil cases, 1757-1850, religion, 1788-1842, mining, 1779-1842, quarrying, 1798-1840, shipping, 1778- [c. 1841], roads and railways, 1834-1839; legal practice records, 1804-1841, and executorship papers, 1841-1855, belonging to Henry Rumsey Williams, and records of his family in Brecknockshire, Monmouthshire and Caernarfonshire, 1881-1928. Records relating to William's political activities have not survived.

Papers of W. A. Madocks, including his memoranda books, letters to John Williams (his agent at Portmadoc), 1806-1825, and some materials for his biography in the form of copies of letters from Ebenezer Thomas (`Eben Fardd'), John Thomas, Chwilog, Ellis Owen, Cefnymeusydd, and others; a 'statute book' of the 'Ancient and Renowned Borough of Tremadoc', 1805-1810, with an account of the Tremadoc Ball and Hunt; together with records from the Harbour Office, Porthmadog, including account books and registers of Portmadoc harbour, 1824-1917. Also included are records of the Festiniog and Blaenau Railway Co., 1866-1883; plans, sections and other records, 1860-1897, of the Aberystwyth and Welsh Coast Railway, the Bala and Festiniog Railway, the Beddgelert Railway, the Caernarvonshire Railway, the Caernarvonshire and Nantlle Railway, the Cambrian Railway, the Corris, Machynlleth, and River Dovey Tramroad, the Corwen and Bala Extension Railway, the Croesor Railway, the Croesor and Portmadoc Railway, the Festiniog Railway, the London and North Western Railway, the Merionethshire Railway, the Portmadoc, Beddgelert and Rhyd-ddu Railway, and the West Midland, Shrewsbury and Coast of Wales Railway; a register of shareholders and minute books of the Festiniog Refreshment House Company, 1878-1890; a minute book and share ledger of the Penrhyndeudraeth Lead Mining Company, 1875-1882; nominal and muster rolls of the Caernarvonshire Volunteers, 1860-1883, and other Caernarfonshire militia records; a minute book and papers relating to collections in Caernarfonshire towards Queen Victoria's Jubilee, 1886-1887; account books relating to slate quarries and to shipping, and miscellaneous Caernarfonshire material, 1723-[19th century].

'Geirlyfr William Lleyn'; 'Bardhoniaeth ... William Middelton'; pedigrees and arms, mainly of North Wales families; 'cywyddau', 'awdlau', etc. by Adda Fras, Iolo Goch, Maredudd ap Rhys, Robin Ddu, Rhys Nanmor, Gwilym ab Ieuan Hen, Dafydd Gorlech, Tudur Aled, Gruffudd ab Ieuan ab Llywelyn Fychan, Wiliam Llŷn, Sion Cent, Sion Tudur, Thomas Prys, Lewis Menai, Gruffudd Phylip, Richard Cynwal, Edmwnd Prys, Wmffre Dafydd ab Ifan, Wiliam Phylip, Sion Bryncir, Siôn Phylip, Richard Phylip, Sion Dafydd Lâs [John Davies], Watcyn Clywedog, Mor[u]s Dwyfech [Morus ap Dafydd ab Ifan ab Einion], Huw Lewis, Dafydd ap Hwlcyn ap Madog, Rhisiart Brych, Dafydd Jones ('Ficer Llanfair-Dyffryn-Clwyd'), Owen Gruffydd, Sion Lleyn [John Roberts], Taliesin, Rhys Goch Eryri, Dafydd Llwyd ap Llywelyn ap Gruffudd, Sion Roger, Sypyn Cyfeiliog [Dafydd Bach ap Madog Wladaidd], Bedo Brwynllys, Mathew Owen, Edward Morus, Huw Mor[y]s, Ieuan Dew Brydydd, Huw ab Ifan, Robert Davies (Nantglyn), Robin ab Iorwerth, Rolant Huw (Graienyn), Dewi Wyn [o Eifion] [David Owen], Griffith William (Braichtalog), Goronwy Owen, John Thomas (Pentrefeidiog) [i.e. Pentrefoelas], M[organ] D[avies], Griffith Puw, Dafydd Jones ('Tailiwr'), William ab Edward ('o'r Bennar'), Thomas Edwards ['Twm o'r Nant'], Lewis Morris, Ieuan Llwyd [Brydydd], Rhys Llwyd [Pant-y-piod], Rolant [Rowland] Jones (Pandy) [Roli Penllyn], Hugh Jones (Llangwm), John Jones [Jac] (Glan y Gors) and W[illiam] Jones [Bardd Môn]; 'englynion' by several authors; material relating to persons and places in Merioneth.

Transcripts of documents relating mainly to Merioneth: Instructions from the Council in the Marches to suppress felonies; charges to juries; a letter, with answer, to a gentleman in Wales touching suits in the Court of Star Chamber, 1598; a letter of recommendation of John Vaughan of Cair gay, 1601; a petition of the freeholders of Estymaner and Talpont; instructions to the Council in the Marches, 1606; a letter of Enianus, bishop of Bangor, to Lord John de Grey, 1310; orders for securing the peace of the Commonwealth; orders at Quarter Sessions, 1673; sentences against Hugh Nanney for incontinence, 1588, 1594; observations on tenures in Englefleld, Flintshire, and concerning a court held by Mr Mackworth; an order in the suit of Robert Lloyd v. Griffith Nanney, 1603; the opinion of George Lee concerning a Portuguese ship wrecked on the Merioneth coast, 1746; a draft petition for an Act to enclose Traeth Mawr and Traeth Bychan; a contract to erect a shire hall at Dolgelley, 1606; the divisions of Merioneth with their proportional assessments, 1689; a canvass for Mr Vaughan and a copy of R. W. Vaughan's address to Merioneth electors, 1796; a rental of Robert Morgan's estate; and the petition of Sir Robert Heath to Charles I.
Instructions to Sir William Bowes, Robert Bowes, and Lord Eure (Scottish border, 1589-1599), Sir George Carey in Ireland with the Earl of Essex, 1598, Mr Carrow Raleigh concerning musters, and Sir Thomas Shirley, Lord Sheffield, Dr Dale, and Mr Bodley (Low Countries, 1586-1598); instructions concerning the expedition to Spain, 1596; papers relating to the proposed Spanish marriage, 1623; speeches and petitions in Parliament, 1623-1626; a list of grants to the Duke of Buckingham and proceedings relating to his impeachment, 1626; and a letter by Ra: Eure, John Harbert, and Daniell Dunn from Breme, 1602.
Printed proclamations of the assumption of the style of King of Great Brittaine by James I, 1604, and of the calling in of testons, 2 Edward VI.
On the back of the former is a fragment of a Welsh poem beginning - 'a fi'n eiste'n obrydd...'

A group of documents relating to gold mining in Merioneth. It includes notes on various gold mines in the county; correspondence addressed principally to O. Parry Hughes, 1918-36; typescript evidence prepared for the Merioneth Gold Mining Inquiry, 1930, and a report of the proceedings; memoranda relating to the formation and development of the Merioneth Mining Development Committee, 1930; copies of printed reports by Professor Henry Louis on the possibilities of gold mining in Merioneth, 1930; notes on diamond drilling and its possibilities in Merionethshire; together with a few printed items, two photographs, press cuttings and miscellanea.

Family papers of the Williams family of Castell Deudraeth, 1859-1929, including a bound volume containing papers, including letters and press cuttings, relating to the general election of 1859 in Merionethshire in which David Williams stood as a Liberal against the sitting Conservative Member W. W. E. Wynne of Peniarth; scrapbooks, 1903-1929, containing press cuttings concerning the family, notably Sir Arthur Osmond Williams, and two typescript essays.

Development Board for Rural Wales records, containing minutes and other papers of the Board and various committees, 1977-1994; general administrative files concerning the establishment of the Board, its functions and responsibilities, and correspondence with other organizations, 1966-1990; construction files containing correspondence, contracts and estate plans relating to housing and industrial developments executed by the Board, particularly in Newtown, 1968-1993; records such as correspondence, minutes, notes and other papers relating to research studies on economic and social life in Mid-Wales carried out by the Board, 1968-1995; files relating to the Board's marketing and promotional strategy, 1978-1991; and press releases, 1977-1990; Mid-Wales Development Corporation records, 1962-1979, including annual reports, 1969-1977, minutes and papers of the Board and various committees, 1968-1979, and seal registers relating to MWDC projects, 1968-1976, containing compulsory purchase orders, contracts, leases and other documents.

An additional three files relating to the Development Board for Rural Wales, being DB/CF/101/1; DB/CF/101/2; DB/CF/101/3 – (Extension to Goodall & Swanwick factories at Dolgellau; factories at Dolgellau; and extension to Marian Park Industrial Estate, Dolgellau). These remain uncatalogued, and are closed for ten years from the date of the latest document in each file.

Papers, 1679-1983, of and accumulated by H. Noel Jerman, comprising: research papers, 1914-1975; files relating to his work in the Secret Intelligence services, 1941-1945; correspondence, notes and other papers relating mainly to archaeology, and also to his professional activities, 1948-1983; 'Notes and Memoranda' relating to events organised by the Cambrian Archaeological Association, 1883-1894; original records collected by him, 1679-1926, including deeds and documents relating to properties in Kerry, Montgomeryshire, 1679-1885, and Kerry School, 1843-1873, and copies of local newspapers, 1834-1868; records relating to the Dolforgan estate, including deeds and documents relating to properties in Montgomeryshire, Carmarthenshire and Merionethshire, 1807-1910, financial records, 1889-1939, and letter books, 1892-1930.

An additional consignment of materials of, and accumulated by, the late H. Noel Jerman (1909-1994), including his research papers relating to properties in Kerry and surrounding areas, papers relating to the Dolforgan estate, together with maps, sale catalogues, plans and photographs, and a lithograph of Dolforgan Hall by T. Way. This group remains uncatalogued.

Deeds, documents and probate records, 1617-1853, relating mainly to the parishes of Caerhun, Conwy, Dwygyfylchi, Gyffin, Llanbedrycennin and Llannor, Caernarfonshire, and to the Abbey estate, in Denbighshire, Merionethshire and Caernarfonshire, 1811-1819; notes on sermons, 1861-1889; and miscellaneous papers relating to Amlwch, Anglesey, 1801-1868.

Deeds, 1490-1977, including deeds and documents mainly relating to properties on Anglesey, Caernarfonshire, Merionethshire and Middlesex, 1675-1977; and deeds relating to properties in Finchley, Middlesex, 1490-1796.

Ledger and journal of Gaewern Slate works, Machynlleth, 1835-1856; accounts and notebooks of the Ratgoed and Cymerau Slate Quarries, Tal-y-llyn, and Llwyngwern Slate Quarry, Llanuwchllyn, 1853-1899; ledgers and notebook of the Cambrian Slate Works, Machynlleth, 1899-1909; minute books of the Abercorris Slate Quarry Company, Rhiwgwreiddyn, Corris, 1893-1909, and the Towyn Company, Tywyn, 1893-1903; and miscellaneous accounts and ledgers, 1827-1909.

Traethawd 'Golwg ar hanes ardal Llawrybetws neu Nantffreuer: o Bethel i lawr i Gaefaes' a ysgrifennodd D. Tecwyn Lloyd ar hanes lleol bro ei febyd, 'o gof personol ac amryfal gofnodion', gan ganolbwyntio ar anheddau'r ardal.

Papers of Henry Robertson, comprising personal and estate papers, 1829-1907; records of a very large number of Welsh railway undertakings, 1786-1911, comprising books of reference, surveryors' notebooks, acts of parlimaent, bills and estimates, conveyances and other title deeds, specifications and tenders, prospectuses and miscellaneous papers; office papers, correspondence and miscellaneous professional papers, 1824-1903; papers relating to several clubs and societies, 1888-1907; and printed books and papers, 1786-[c.late 19th cent.].

Papers relating to the administration of the Plas Power estate and household, including some properties belonging to the Chirk estate, some but not all of which became part of the Plas Power estate; also included are some records from other properties in England that were owned by the Myddelton family.

A volume, 1906, containing lists of communicants in the Diocese of Bangor, relating specifically to Montgomeryshire and Merionethshire.

A volume, 1906, containing completed financial returns, issued by the Welsh Church Commission, and balance sheets of parishes in the Diocese of Bangor, relating specifically to the Archdeaconry of Merioneth.

Papers relating to families and estates in north Wales, including the West family, the Chirk Castle estate, the Hengwrt, Rug and Nannau estate, the Wynnstay estate, the Penbedw estate, the estate of Richard Willding of Llanrhaeadr Hall, Denbighshire, and the Whitehall-Davies family of Broughton Hall, Flintshire, and Llannerch, Denbighshire. Records and correspondence, including relating to abstracts of title, chapels, churches, conveyances, inclosures, industrial activity, law suits, mining, parliamentary elections, probate, railways, schools and tithe commutation. Office records, including cash journals, bill books and letter books, [19th century]-[20th century].