A papers written by Elfyn Llwyd on the use of the Welsh language in criminal courts in Wales.

The file comprises Cymdeithas yr Iaith Gymraeg ephemera including a 1993 calendar, stickers, posters and flyers relating to various campaigns including "Mwy na Miliwn" and "Cymunedau Byw".

Various pamphlets relating to the Welsh language including material on holiday homes, education and the target to have a million Welsh speakers.

Cyhoeddiadau a phapurau ymchwil G. J. Williams ar yr iaith Gymraeg, gan gynnwys llawysgrif ei draethawd ymchwil, 'The verbal forms in the Mabinogion and Bruts'; darlithoedd ac erthyglau amrywiol ar hanes yr iaith, yr iaith lafar, gramadeg a geirfa, enwau, yr ieithoedd Celtaidd, ac addysg Gymraeg; ynghyd ag ychydig bapurau perthynol i'w waith fel aelod o fwrdd golygyddol Geiriadur Prifysgol Cymru.

Llythyrau, 1915-1977, at Elizabeth Williams, nifer yn ymwneud â G. J. Williams a chyhoeddi ei waith; capel Bethesda'r Fro; dyfodol yr iaith Gymraeg; Undeb Cymru Fydd a Phlaid Cymru. Ymhlith y gohebwyr amlycaf mae Glyn Ashton, Rachel Bromwich (2), D. Simon Evans (4), Aneirin Talfan Davies, Cassie Davies, Rachel Ellenborough (21, ynghyd â pheth o'i gwaith dan yr enw Rachel Law, a gwybodaeth yngŷn ag achau'r teulu (Iolo Morganwg)), Gwynfor Evans (2), Raymond Gower, Bedwyr Lewis Jones (2), Bobi Jones (2), D. Gwenallt Jones (3; ac 1 oddi wrth Nel Gwenallt ar farwolaeth ei gŵr), E. D. Jones (6), Ceri Lewis, Saunders Lewis (3; un oddi wrtho at ei wraig, Margaret, pan oedd yn y carchar; a 3 oddi wrth Margaret at Elizabeth Williams; ac 1 llythyr, 1931, at Saunders Lewis oddi wrth J. Alun Pugh), Timothy Lewis (2), T. J. Morgan, Rhys Nicholas, Iorwerth Peate, Eurys Rowlands, R. J. Thomas (6), a D. J. Williams (6).

Torion papur amrywiol, 1934-1978, y mwyafrif yn cynnwys cyfeiriadau at genedlaetholdeb, addysg Gymraeg, a chrefydd a diwylliant Cymru. Ymddengys mai torion a grynhowyd gan Elizabeth Williams yw'r rhain, ac yn eu plith mae erthyglau ganddi hi a G. J. Williams ar yr iaith Gymraeg. Ceir hefyd nodiadau ar ddiwylliant, crefydd ac iaith, nifer gan ac yn llaw Elizabeth Williams.

Comprises Gwilym Prys-Davies' political papers, 1954-2008, including letters, articles, minutes and reports, as well as subject files, 1912-2012, and letters between Harri Webb and John Legona and some papers relating to William Abraham (Mabon). The papers relate mainly to devolution, Welsh language legislation, language rights and contain files relating to the Welsh Republican Movement and civil rights group Cefn.
Papers relating to the funeral of Gwilym Prys Davies, 8 April 2017, comprising the order of service, tributes and a booklet containing family photographs; April 2017.
Five letters, 2005-2006, from Gwilym Prys Davies to Prys Davies and Meri Huws of the Welsh Language Board, together with three attached documents; September 2018.

General correspondence and political papers including material related to the Welsh Hospitals Board, the Welsh language, Welsh language legislation, devolution, the Labour Party, elections and broadcasting.

A printed report by a sub-committee of the Cymmrodorion Council on the use of the Welsh language in elementary schools in Welsh speaking districts, 8 September 1884, printed for a meeting of the Society at Liverpool, 18 September 1884. Printed by Whiting and Co., Sardinia Street, London

The file includes correspondence between Ffred Ffrancis, Chairman of Cymdeithas Yr Iaith Gymraeg (The Welsh Language Society), and Hywel I Evans concerning the Welsh language in the curriculum, 1988-1991.

The file comprises correspondence and papers, 1989-1991, relating to the meetings of the Welsh Language Working Party set up by the Labour Party Wales, including agenda, minutes and reports.

The file consists of parliamentary papers relating to the attitudes and policies of the Labour Party towards the Welsh language.

The file consists of a manuscript report entitled 'Labour and the Welsh language: an integrated policy' prepared by Gareth Howells, Cardiff, April 1973.

Two volumes of miscellaneous transcripts mainly in the hand of Walter Davies (Gwallter Mechain, 1761-1849), relating to the antiquities, history, topography, language, and literature of Wales. They include catalogues of Welsh manuscripts; transcripts of manuscripts of Evan Evans (Ieuan Brydydd Hir), of letters of Edward Lhuyd, Lewis Morris, Goronwy Owen, etc., of Strata Marcella abbey charters, of monumental inscriptions, of Evan Evans's transcripts of Richard Farrington's archaeological notes, etc.; notes on Llanerfyl, Llangadfan, and Garthbeibio, written by William Jones, Llangadfan, and sent by him, with letters, to Walter Davies; a letter, 1792, from Edward Williams (Iolo Morganwg) to Walter Davies; an extract, by Lewis Morris, from his Celtic Remains; Marwnad Lewis Morys ... by Goronwy Owen, in the autograph of Evan Evans; etc. Both volumes are indexed.

Three volumes of transcripts and notes made by Walter Davies, including extracts relating to the history, language, topography, and archaeology of Wales, 'englynion' and other poems, extracts from the Bible, etc.

Miscellaneous notes and extracts made by Walter Davies and dealing with the language, literature, and agriculture of Wales.

'Diquisitions by Various Persons on the Welsh Language and Welsh Poetry', being transcripts by John Jenkins of letters, 1821, in The Gentleman's Magazine, etc., by David Williams (Rumsey, Hants.), John Parry ('Bardd Alaw'), and Walter Davies.

'Casgliad o eiriau yn y Beibl Cymraeg, sydd naill ai wedi newid eu hystyr, ney ynte wedi myned allan o arferiad, ynghydag eglurhad arnynt', written for 'Cyfarfod Llenyddol y Bala, Nadolig, 1886'.