Correspondence of David Thomas, 1907-1929, together with pamphlets, reports and other printed items relating mainly to socialism, the Independent Labour Party, workers' unions, agricultural wages, publication of Y Werin a'i Theyrnas, local committees in North Wales for improvement of social conditions, the Caernarfonshire parliamentary election, 1922, and miscellaneous unspecified subjects; incomplete copies of David Thomas's printed works, articles and parts of his thesis, 1928; account books, [c. 1878]-1910, belonging chiefly to John Williams, Bwlchgwyn, Denbighshire; a small notebook containing literary adjudications in connection with an eisteddfod at Tal-y-sarn, 1908, and translations of six stories from French into Welsh by Morfudd' [Miss H. Jones, Porth] andNehushtan' [N. El. Thomas, Swansea], entered at the Barry National Eisteddfod 1920.

Papers relating to Harold Jones's efforts as an individual and as a member of the Plaid Cymru Trade Union Group to secure the establishment of a Wales T.U.C., 1965-1974, comprising mainly correspondence, 1965-1974, pamphlets, 1968-1974, and newspaper cuttings, 1965-1974.

Papers and ephemera relating to the Peace Movement, 1976-[1990s]; the Labour Party, 1975-1996; Trade Union activities, [c. 1980s]-[1990s]; the Peace and Nuclear Disarmament movement, 1976-[1990s], including the Greenham Common Peace Camp, the 'Peace Marches' from Cardiff to Greenham Common, the camp at Brawdy Royal Air Force base, Pembrokeshire, and other women's peace camps, and the Campaign for Nuclear Disarmament (CND); Nuclear Energy and Green Movement, 1973-[1990s]; feminist issues, 1958-1990; issues including animal rights, Europe, the NHS, pensions, public transport, the Poll Tax, unemployment and the United Nations, [c. 1990s]; posters relating to the activities of the various groups and societies supported by them, [c. 1980s]-[1990s], regarding numerous issues, campaigns and events, including the peace movement, the environment, human rights and the 1989 `War on Want' Benefit Concert for Central America, and correspondence with MPs, 1982-1992.

Political and professional papers of W. H. Mainwaring, 1910-1970, including papers relating to the Cambrian Combine Collieries dispute, 1910-1911; the manuscript of the publication, The Miners' Next Step, 1912; papers relating to the South Wales Miners' Idustrial Union, 1928-1932; correspondence, 1905-1970, and pamphlets of economic and Socialist interest, [late 19th cent.] - [early 20th cent.].

Correspondence and papers, 1970, relating to a symposium of trade unions in Wales, assembled together by the donor Dr H. G. Alun Hughes.