Mae'r archif yn cynnwys: pamffledi, cylchlythyron etc., amrywiol; dwy gyfrol o gofnodion cyfarfodydd Pwyllgor Canolog (1967-70) a Senedd (1970-Ionawr 1975) Cymdeithas yr Iaith Gymraeg a rhai y cyfarfodydd cyffredinol blynyddol; cofnodion y Senedd,1974-1981 ac adroddiadau gan wahanol grwpiau o'r Gymdeithas, 1976-1981; papurau gweinyddol,1970-1981, yn cynnwys copïau o benderfyniadau a gyflwynwyd yng nghyfarfodydd cyffredinol y Gymdeithas a deunydd printiedig; papurau yn ymwneud â Grŵp y Dysgwyr, 1974-1985; papurau yn ymwneud â Mudiad Rhyddid yr Iaith, 1977; papurau yn ymwneud ag ymgyrchoedd y bu'r Gymdeithas yn eu canlyn,1970-1981, gan gynnwys yr ymgyrch dros sianel deledu Cymraeg; ffeiliau gohebiaeth,1966-1986; ffeiliau swyddfa,1971-1981; datganiadau i'r wasg etc., 1970-1990; cofnodion y Senedd,1979-1991; ffeiliau amrwiol,1975-1991; papurau yn ymwneud â darlledu, 1974-1980; ffurflenni aelodaeth, 1979-1990; papurau ynghylch y grŵp addysg, 1982-1989; papurau ynghylch tanysgrifiadau i Tafod y Ddraig, 1980-1990; llyfrau lloffion, 1965-1967, yn cynnwys papurau yn adlewyrchu ymgyrchoedd a gweithgareddau y Gymdeithas; cofnodion cyfarfodydd, 1966; atgofion am sefydlu'r Gymdeithas yn 1962 a'i datblygiad cynnar; amrywiol dorion o'r wasg; a phosteri amryfal. Y mae grŵp Mai 1996 yn cynnwys papurau, 1971-1993, yn ymwneud â gwahanol ranbarthau y Gymdeithas a phapurau,1984-1993, yn ymwneud â'i chynghorau, cyfarfodydd seneddol etc. Y mae'r grŵp mawr o gofnodion a dderbyniwyd ym mis Gorffennaf 1998 a mis Ionawr 1999 yn cynnwys y canlynol: llyfrau lloffion,1971-1996,yn cynnwys torion o'r wasg yn disgrifio ymgyrchoedd a gweithgareddau y Gymdeithas a bywyd gwleidyddol Cymru; papurau yn ymwneud ag Eisteddfod Genedlaethol yr Urdd a'r Eisteddfod Genedlaethol, 1986-1994, gohebiaeth oddi wrth y Swyddfa Ganolog,1988-1997; papurau ynglŷn â chelloedd a rhanbarthau y Gymdeithas, 1977-1996; papurau gweinyddol, 1977-1998, yn cynnwys dyddiaduron swyddfa, rhestrau aelodaeth, papurau yn perthyn i wahanol swyddogion y Gymdeithas, papurau ynglŷn â grŵp addysg y Gymdeithas, deunydd yn deillio o lawer o ymgyrchoedd y Gymdeithas, papurau ynglŷn â chyrsiau ar gyfer dysgwyr, papurau ynglŷn â'r Ddeddf Eiddo, a datganiadau i'r wasg. = The archive comprises: a series of forms bearing signatures supporting the Welsh Language Society's Petition to the new local authority bodies in Wales requesting them to strengthen the Welsh Language and Welsh Society; a series of forms bearing signatures supporting the Society's declaration of support for the workers of Shotton; miscellaneous pamphlets, circulars; etc.; two volumes of minutes of meetings of the Central Committee (1967-70) and Senate (1970-January 1975) of the Welsh Language Society and of some of the annual general meetings; minutes of the Senate, 1974-1981 and reports from various groups of the Society, 1976-1981; administrative papers, 1970-1981, including copies of resolutions presented to the general meetings of the Society and printed matter; papers concerning the Learners' Group, 1974-1985; papers concerning the Language Freedom Movement, 1977; papers concerning the campaigns pursued by the Society, 1970-1981, including the campaign for a Welsh language television channel; correspondence files, 1966-1986; office files, 1971-1981; press releases etc., 1970-1990; Senate minutes, 1979-1991; miscellaneous files, 1975-1991; papers relating to broadcasting, 1974-1980; membership forms, 1979-1990; papers concerning the education group, 1982-1989; papers concerning subscriptions to Tafod y Ddraig, 1980-1990; scrapbooks, 1965-1967, containing papers reflecting the campaigns and activities of the Society; minutes of meetings, 1966; reminiscences on the establishment of the Society in 1962 and its early development; miscellaneous press cuttings; and miscellaneous posters. The May 1996 group comprises papers, 1971-1993, relating to the various regions of the Society and papers, 1984-1993, relating to its councils, parliamentary meetings etc. The large group of records received in July 1998 and January 1999 comprise the following: scrapbooks, 1971-1996, containing press cuttings describing the campaigns and activities of the Society and Welsh political life; papers relating to the Urdd National Eisteddfod and the Welsh National Eisteddfod, 1986-1994, correspondence from the Central Office, 1988-1997; papers concerning cells and regions of the Society, 1977-1996; administrative papers, 1977-1998, including office diaries, membership lists, papers belonging to various officials of the Society, papers concerning the Society's education group, material deriving from many of the Society's campaigns, papers concerning courses for Welsh learners, papers concerning the Property Act, and press releases.

Papers, 1889-1988, of Ben G. Jones, including academic notes, 1932-1935; personal letters, 1942-1968; political papers, 1935-1985; correspondence relating to politics in Merionethshire, 1963-1967; press cuttings, 1958-1963, printed material relating to the four main political parties in Wales, 1949-1966; papers relating to the Honourable Society of Cymmrodorion, 1939-1988; minute book, 1889-1909, of the London Welsh Mutual Improvement Societies' Union; papers deriving from the compilation and publication of the Dictionary of Welsh Biography, 1953-1986; papers relating to his public life, 1968-1984, including the Kilbrandon Commission, 1936-1969, the BBC, 1968-1978, UCW Aberystwyth, 1968-1985, and the Agricultural Land Tribunal, 1980-1984; minute book, 1889-1909, of the London Welsh Mutual Improvement Societies' Union; and papers relating to the status of the Welsh language and to teaching and broadcasting through the medium of Welsh, 1965-1987.

Miscellaneous papers, 1970-1985, relating to Welsh broadcasting, mainly television, including papers on the development of the BBC television service, the campaign to secure a Welsh language television channel, the role of the Broadcasting Council for Wales, the stand made by Gwynfor Evans in 1980, the 1981 Broadcasting Act, and the establishment of S4C. The correspondents include Alun Talfan Davies, 1972, Gwynfor Evans (4), 1972-1980, Cledwyn Hughes (3), 1980, Glyn Tegai Hughes (3), 1972-1973, Emyr Jenkins, 1980, Jâms Nicolas (James Nicholas), 1980, Alwyn D. Rees (2), 1972, Gwilym Williams, Archbishop of Wales (2), 1973-1980.

Minutes of the meetings of the Council, 1949-1959; memoranda, reports and notes deriving from the activities of the Council, 1949-1959, together with subject files covering regional devolution, trade at the south Wales ports, transport services in Wales, employment and the repopulation of the rural areas, a Welsh Television Service, functions exercised by the Welsh Office, and the Welsh economy.

Records and papers collected by Emrys Roberts, 1945-1983, including correspondence and papers relating to the National Eisteddfod, 1959-1976; the Development Board for Rural Wales, 1973-1981; and Wales (West and North) Television Ltd, 1960-1967. There are also papers relating to other committees on which Emrys Roberts sat, 1967-1983, and other miscellaneous papers, 1945-1981.

Letters addressed to Huw T. Edwards, 1929-1970, and carbon copies of letters sent by him, 1945-1969, concerning politics, literature, and the Council for Wales and Monmouthshire, including letters to and from political figures in the Labour Party and Plaid Cymru, and Welsh literary figures; pocket diaries, 1929-1968; minute books of the North Wales Labour Federation, 1923-1930; reports and memoranda concerning the activities of the Council for Wales and Monmouthshire, political life in North Wales, and the activities of TWW, 1935-1966; press cuttings relating to Edwards' political career and the activities of the Council for Wales and Monmouthshire, 1930-1968; illuminated addresses and distinctions presented to him, 1933-1969; miscellaneous printed items, 1912-1967; poems by him, 1950-1958; and other personal papers, 1926-1967; and acquired papers, notably letters from Sir Owen M. Edwards to Hughes and Son, Wrexham, printers, 1894-1895.

Correspondence and papers relating mainly to Lord Hooson's political career, including papers regarding parliamentary questions, 1967-1978; the Welsh Liberal Party, 1963-1979; Montgomery County Liberal Association 1965-1979; Welsh Affairs, 1961-1978; University College of Wales, Aberystwyth, 1961-1968; Dyfed-Powys Constabulary, 1970-1976; foot and mouth disease in Wales, 1967-1968; transport problems in Mid-Wales, 1962-1974; National Theatre for Wales, 1968-1969; Rural Development Board for Wales, 1967-1970; Mid-Wales Hospital Service, 1972-1973; Farmers Union of Wales, 1966-1973; Aberfan Disaster, 1966-1967; television and radio reception in Wales, 1969-1976; Wales Tourist Board, 1968-1976; Plaid Cymru, Welsh nationalism, Welsh language, Devolution, Federalism, Welsh economy, unemployment, Rhondda West by-election, etc., 1960s-1970s; the Liberal Party correspondence, 1960s-1970s, Liberal Party organisation and policies, 1967-1971; Liberals and the Industrial Relations Bill, 1971-1973; Lib-Lab pact, 1977-1978; Liberal Foreign Affairs Panel, 1966-1967; NATO and the North Atlantic Assembly, 1966-1978; correspondence files of the Welsh Liberal Party, 1966-79; engagement diaries, 1966-1978; typescript speeches and notes for speeches, 1960s-1970s; parliamentary accounts, 1970-1972; miscellaneous speeches, press statements, newspaper cuttings, etc., 1960s-1970s; political papers [c. 1950]-1973, produced by various parties; Local Government Reform in Wales, 1993-1994; the Liberal Party's Pantyfedwen Conferences, 1956-1963; the London Welsh School, 1983-1993, the Llangollen International Eisteddfod, 1986-1997; the provision of speech therapy and physiotherapy in Clwyd, 1984-1990; constituency correspondence and papers, [1960]-1979; personal correspondence, 1965-1979; and correspondence, press releases and newspaper cuttings relating to Jeremy Thorpe, former leader of the Liberal Party, 1967-1979; together with papers relating to his business interests including, Laura Ashley Holdings Plc., 1984-1997; Severn River Crossing Plc, 1990-1997; and his legal career, 1949-1962. A further collection of Lord Hooson's papers were received in May 2011 - this group remains uncatalogued.

Papers of Aneirin Talfan Davies, 1911-1980, consisting of diaries, 1956-1980; papers relating to his work with the BBC, including letters and scripts, [1940s]-[1970]; correspondence, drafts and notes reflecting his literary activities, including his lectures, books, articles, libretti and his editorial duties on Barn (there is comparatively little of his poetry present), 1941-[1979]; material such as letters, radio scripts and articles relating to literary figures such as Dylan Thomas, David Jones and T. Rowland Hughes, 1937-1973; correspondence and minutes of meetings, in connection with Llyfrau'r Dryw / Christopher Davies (Publishers) Ltd., Yr Academi Gymreig, The Guild for the Promotion of Welsh Music, the Welsh Arts Council, and a number of bodies within the Anglican Church in Wales, 1971-1977; letters from various prominent Welsh literary figures and successive Archbishops of Wales, 1972-1980; several volumes of press cuttings, 1911-1977; and personal papers, 1963-1974.

Personal correspondence, 1916-1954; study notes, 1902-1952; biographical material, 1903-1954; notebooks entitled 'Tennyson Biography'; sermons and addresses, 1932-1952; orders of service for Victory, 1945, the United Nations 1946, Human Rights Day, 1951-1954, the Coronation and other occasions, 1931-1954; religious and international affairs, 1944-1945; Welsh Book Festivals, 1935-1938; Welsh School of Social Service, 1911-1940; The Gregynog Conferences on International Education, 1922-1937; Advisory Education Committee minutes, 1926-1929; international co-operation, 1933-1937; Welsh nationalism, 1910-1943, including nationalists' attitudes towards World War II, 1939-1941; broadcasting materials mostly of Marconi and Kemp, 1931-1953; Welsh broadcasting, 1923-1948; the Welsh Children's Peace Message, Pageant, and Wales and the Peace Movement, 1923-1955; BBC staff changes and administration in Wales, 1934-1952; the League of Nations, 1923-1952; the Welsh National Council of the League of Nations Union, 1923-1945; United Nations, 1942-1954; UNESCO, 1925-1947; addresses, radio talks and notebooks on the international situation, 1930-1954; Council for Education in World Citizenship, 1940-1950; London International Assembly, 1941-1944; Welsh Committee of the UNESCO, 1949-1953 and human rights materials, 1945-1953.

Papers of Sir Ben Bowen Thomas (1899-1977), educationalist and public servant, comprising autobiographical material on his career, interests and family, 1954-1972; biographical articles and an interview, 1964-1966; letters to his wife and daughter with references to his work with UNESCO and Welsh educational matters, 1947-1960; letters from Dr Thomas Jones and Sir Percy E. Watkins relating to educational issues and Coleg Harlech, 1926-1955; correspondence concerning BBT's work with UNESCO, 1954-1962; miscellaneous correspondence, 1948-1976; addresses and speech notes, 1949-1977; pamphlets, offprints and articles, 1941-1973; research notes on regions and towns of Wales during the 18th and 19th centuries; circulars, articles, reports, etc. relating to education and educational bodies in Wales, 1942-1975, to UNESCO, 1946-1958, and to public and cultural bodies such as the Welsh Language Council, ITA and the Rural Development Board, 1965-1973; McNair Report on the Training of Teachers, 1942-3; memorials, tributes and obituaries of other educationalists; and miscellaneous press cuttings and notes. The archive also includes a collection of sermon notes and exercise books of his grandfather, the Rev. Benjamin Thomas, (1838-1913), a Baptist minister in Ystrad Rhondda, Glamorgan.

Printed items, typescripts, press cuttings, and some letters, 1963-1994, on the Welsh language. They include material on the 1963 Report of the Council for Wales and Monmouthshire, teaching through the medium of the Welsh language in the University of Wales, parliamentary debates on the status of the Welsh language, broadcasting, bilingual road signs, the use of the Welsh language in the law courts, the Welsh language and the education system, the 1971 Census, publishing in the Welsh language, and Welsh language television.

Papurau'r cymdeithasegydd Alwyn D. Rees, 1911-1974, yn cynnwys papurau'n ymwneud â Phrifysgol Cymru, yn bennaf â Choleg Prifysgol Cymru, Aberystwyth, 1920au-1974, gan gynnwys papurau'n ymwneud â'r comisiwn a sefydlwyd i archwilio strwythur ffederal Prifysgol Cymru yn y 1960au; papurau ynglŷn â lle'r Gymraeg yn y Brifysgol a'r ymgyrch i sefydlu neuadd Gymraeg i fyfyrwyr yn Aberystwyth,1967-1974; papurau'n ymwneud â llyfrau, erthyglau a darlithoedd Alwyn D. Rees, 1933-1973, a Chymdeithas yr Iaith Gymraeg, [c.1964]-1974; papurau'n ymwneud â Barn, 1966-1967; papurau'n ymwneud â darlledu yng Nghymru, 1938-1974; papurau'n ymwneud â'r diwydiant llechi yng Nghymru,1946; papurau'n ymwneud â gwleidyddiaeth yng Nghymru, 1911-1974; gohebiaeth gyffredinol, 1935-1974; a phapurau a gohebiaeth bersonol , 1930-1974 = Papers of the sociologist Alwyn D. Rees, 1911-1974, including papers relating to the University of Wales, mainly the University College of Wales, Aberystwyth, 1930s-1974, including papers relating to the commission established to examine the federal structure of the University of Wales in the 1960s; papers concerning the place of the Welsh language in the University and the campaign to establish a Welsh student hostel at Aberystwyth, 1967-1974; papers relating to the University of Malta, 1940-1951; Alwyn D. Rees's research papers, 1933-1973; papers relating to Alwyn D. Rees's books, articles and lectures, and further related research papers assembled by him, 1925-1974; papers relating to the Welsh language, 1952-1974, and 'Cymdeithas yr Iaith Gymraeg', [c. 1964]-1974; papers relating to 'Barn', 1966-1975; papers relating to broadcasting in Wales, 1938-1974; papers relating to the Welsh slate industry, 1946; papers relating to politics in Wales, 1911-1974; general correspondence, 1935-1974; and personal papers and correspondence, 1930-1974.

Papurau William Andreas Jones, [1935]-[1988], gohebydd y wasg i Bwyllgor Etholaeth Arfon o Blaid Cymru a llythyrwr cyson i'r wasg, gan gynnwys llythyrau oddi wrth Anthony Wedgwood Benn (2), Neil Kinnock, John Morris a Dafydd Iwan (2), torion o'r wasg yn ymwneud â Phlaid Cymru a'r Bedwaredd Sianel, a'i atgofion cynnar.

Papurau gwleidyddol Dafydd Elis Thomas, yn cynnwys adroddiadau a datganiadau i'r wasg, 1975-1991; areithiau ac erthyglau, 1980-1990; gohebiaeth gyffredinol a gwahoddiadau, 1974-1992; gohebiaeth, nodiadau ar drafodaethau a phapurau eraill yn ymwneud â gwaith Tŷ'r Cyffredin, 1974-1992, a Llyfrgell Tŷ'r Arglwyddi, 1980-1991; gohebiaeth â'r Swyddfa Gymreig, 1974-1990; papurau'n ymwneud â Phlaid Cymru, 1974-1992; papurau'n ymwneud â materion lleol, yn bennaf rhai Meirionnydd Nant Conwy a Gwynedd, 1972-1991, a materion rhyngwladol, 1971-1991; a phapurau'n ymwneud ag addysg yng Nghymru, yn cynnwys y Cwricwlwm Cenedlaethol ac addysg bellach, 1974-1991, amaethyddiaeth ac Undeb Amaethwyr Cymru, gan gynnwys lles anifeiliaid ac effaith trychineb Chernobyl ar ffermio defaid yng Nghymru, 1975-1991, diwydiant yng nghefn gwlad, Bwrdd Datblygu Cymru Wledig, ac effaith ail-gartrefi,1976-1991, papurau'r Ymddiriedolaeth Genedlaethol a'r celfyddydau, 1974-1991, datganoli, 1977-1992, cyfathrebu a'r cyfryngau, 1976-1992, cyfraith a threfn, 1975-1989, problemau alcohol a phroblemau cymdeithasol, 1975-1991, yr iaith Gymraeg, 1973-1992; diwydiant, 1974-1989, yr economi, 1972-1990, iechyd a nawdd cymdeithasol, 1971-1990, trafnidiaeth, 1975-1989, ac ynni niwclear, 1971-1991 = Political papers of Dafydd Elis Thomas, including reports and press releases, 1975-1991; speeches and articles, 1980-1990; general correspondence and invitations, 1974-1992; correspondence, notes on debates and other papers relating to the business of the House of Commons, 1974-1992, and to the House of Commons Library, 1980-1991; correspondence with the Welsh Office, 1974-1990; papers relating to Plaid Cymru, 1974-1992; papers relating to local matters, mostly Meirionnydd Nant Conwy and Gwynedd, 1972-1991, and international matters, 1971-1991; and papers concerning education in Wales, including National Curriculum and further eduaction, 1974-1991, agriculture and the Farmers' Union of Wales, including animal welfare and the effect of the Chernobyl disaster on sheep farming in Wales, 1975-1991, rural industry, Development Board for Rural Wales, and the effect of second homes, 1976-1991, National Trust and the arts papers, 1974-1991, devolution, 1977-1992, communications and the media, 1976-1992, law and order, 1975-1989, alcohol and social problems, 1975-1991, the Welsh language, 1973-1992, industry, 1974-1989, the economy, 1972-1990, health and social security, 1971-1990, transport, 1975-1989, and nuclear power, 1971-1991.

Sgriptiau a chopïau o sgriptiau, yn Gymraeg a Saesneg yn cynnwys sgyrsiau, 1937-1975; dramâu, 1937-1975; rhaglenni nodwedd, 1937-1975; sgyrsiau nodwedd, 1938-1975; Awr y Plant (sgyrsiau; storiâu, dramâu a rhaglenni nodwedd; ac amrywiol), 1932-1974; ysgolion,1935-1975; Good Morning Wales, 1970-1975; storiâu, 1970-1975; cerddoriaeth,1937-1975; crefydd,1943-1975; rhaglenni chwaraeon,1972-1975; cyfres wreiddiol o sgriptiau y BBC yn Llyfrgell Genedlaethol Cymru, 1935-1977; Wales Today, 1972-1993; a Heddiw, 1973-1982./Scripts and copies of scripts, in Welsh and English comprising talks, 1937-1975; plays, 1937-1975; features, 1937-1975; talks features, 1938-1975; Children's Hour (talks; stories; plays and features; and miscellaneous), 1932-1974; schools, 1935-1975; Good Morning Wales, 1970-1975; stories, 1970-1975; music, 1937-1975; religion, 1943-1975; sports programmes, 1972-1975; original series of BBC scripts at the National Library of Wales, 1935-1977; Wales Today, 1972-1993; and Heddiw, 1973-1982.