Correspondence and papers of T.G.G. Herbert together with historical records acquired by him, 1736-1899, general and political correspondence, 1953-1986, much of it relating to the work of the Ceredigion District Council; papers relating to the Cardiganshire County Council elections, 1955-1972; personal papers, 1936-1988; and papers relating to his son Rhodri Herbert, 1954-1972.

An additional five boxes of papers were donated February 2006. This group remains uncatalogued. A collection of photographs, slides and postcards were received at the same time, which also remain uncatalogued.

Papurau Pwyllgor Rhanbarth Ceredigion o Blaid Cymru, yn cynnwys cofnodion,1939-1984; gohebiaeth,1944-1981; papurau'n ymwneud â gwaith a chyllid y Pwyllgor a'i ganghennau,1959-1971; papurau'r Gynhadledd Flynyddol,1976-1979; torion papur newydd,1970-1975; ymgyrchoedd, 1960-1965; adroddiadau misol Peter Hughes Griffiths, Trefnydd y pwyllgor rhanbarth,1970-1972; papurau Adran Merched Plaid Cymru,1973-1978; ffeiliau'r swyddfa ganolog, 1961-1967, a thaflenni printiedig o'r swyddfa ganolog, 1974-1985; cofnodion Cyngor Talaith Dyfed,1975-1977; gohebiaeth a phapurau ariannol cangen Aberystwyth, 1968-1979; cofnodion cangen Aberystywth,1959-1978; papurau, gohebiaeth a llenyddiaeth yn ymwneud ag etholiadau cyffredinol,1959-[1980au], ac etholiadau lleol,1963-1964. Mae grŵp ychwanegol o bapurau a dderbyniwyd yn 2000 yn dal heb eu catalogio. = Papers of the Ceredigion Area Committee of Plaid Cymru, including minutes, 1939-1984; correspondence, 1944-1981; papers relating to the work and finances of the Committee and its branches, 1959-1971; Annual Conference papers, 1976-1979; newspaper cuttings, 1970-1975; campaigns, 1960-1965; monthly reports of Peter Hughes Griffiths, the area committee organiser, 1970-1972; papers of the women's section, 1973-1978; central office files, 1961-1967, and printed leaflets from the central office, 1974-1985; minutes of the Dyfed Regional Council, 1975-1977; correspondence and financial papers of the Aberystwyth branch, 1968-1979; Aberystwyth branch minutes, 1959-1978; papers, correspondence and literature relating to general elections, 1959-[1980s], and local elections, 1963-1964. A further group of papers received in 2000 remains uncatalogued.

Mae dau grŵp o bapurau ychwanegol yn dal heb eu catalogio.