Cofnodion Swyddfa Ganolog Eisteddfod Genedlaethol Cymru, yn cynnwys cofnodion Cyngor yr Eisteddfod, 1959-1973, ffeiliau yn ymwneud ag eisteddfodau cenedlaethol, 1959 (Caernarfon)-1996 (Bro Dinefwr), a llyfrau lloffion yn ymwneud ag eisteddfodau cenedlaethol, 1963 (Llandudno)-1977 (Wrecsam). = Records of the National Eisteddfod of Wales Central Office, comprising minutes of the Eisteddfod Council, 1959-1973, files relating to eisteddfodau genedlaethol, 1959 (Caernarfon)-1996 (Bro Dinefwr), and scrap books (llyfrau lloffion) relating to eisteddfodau genedlaethol, 1963 (Llandudno)-1977 (Wrecsam).

Papers, 1917-1957, of Winifred Coombe Tennant, mainly relating to 'Gorsedd y Beirdd' and to the National Eisteddfod of Wales. They include correspondence, 1917-1954, concerning the Gorsedd and the National Eisteddfod, her efforts to assist British prisoners of war, 1940-1941, and general interest; minutes, memoranda and reports of various committees associated with Gorsedd y Beirdd, 1922-1954; articles by Winifred Coombe Tennant and other miscellaneous papers, 1918-1947; press cuttings, photographs, postcards, badges and other ephemera, 1917-1954; printed material, including Gorsedd proclamation programmes, 1918-1954, programmes of Gorsedd meetings, 1925-1951, lists of officers and members of the Gorsedd, 1923-1949, 1924-1959, 1947, annual reports of the Eisteddfod Council, 1937-1950, Eisteddfod programmes, 1917-1952, articles and other items relating to Gorsedd y Beirdd and eisteddfodau, 1918-1957.

Cerdd anhysbys i gyfarch eisteddfod, yn cychwyn 'Ha wyr hen ddifyr ddefod...', [20 gan., ¼ cyntaf]. = An anonymous poem addressing an eisteddfod, beginning 'Ha wyr hen ddifyr ddefod...', [20 cent., first ¼].

A collection of poems, 'pryddestau', 'englynion' and other forms by John Lewis, 1860-1864. Many of the poems were successfully entered for competition at local 'eisteddfodau', e.g. at Bridgend, Brecon, Blaenpennal, Llangwyryfon, Tredegar, Aberystwyth ('Rheilffordd Glannau Cymru', 1864), Ebbw Vale, Aberaeron, Talybont, Abermeurig, Llanilar, Rhymney and Cilcennin.

A letter, 15 October 1963, in Welsh, from the novelist Selyf Roberts to Gwilym Rhys Roberts, secretary of the Literature Committee of the 1965 National Eisteddfod in Montgomeryshire, arguing the importance of giving prose equal status to poetry in the National Eisteddfod's competitions and prize ceremonies.

Two notebooks containing addresses given at eisteddfodau, Penny Readings, education meetings, etc.; and Welsh poetry.

Papurau yn ymwneud ag amrywiaeth eang o weithgareddau Brinli yn cynnwys llyfrau ysgol a defnyddiau addysgiadol eraill, 1915-1977; papurau cyfreithiol, yn bennaf gohebiaeth a nodiadau, 1918-1980; cofnodion Cyngor Dosbarth Trefol Maesteg, 1927-1976; papurau Undeb Annibynwyr Cymru, 1931-1976; hanes lleol, 1927-1971; Amgueddfa Genedlaethol Cymru, 1976-1981; deunydd yn ymwneud â'i gyfrolau ar Iolo Morganwg, [1974]-[1979]; Yr Eisteddfod Genedlaethol, 1926-1981, a beirniadaethau eisteddfodol, 1943-1981; torion papur newydd, 1920-1980; rhyddiaith Brinli, 1919-1978, a barddoniaeth, 1932-1981; gweithiau llenyddol eraill ganddo ef ac eraill, 1913-1978; gohebiaeth bersonol, 1909-1981; papurau eraill personol a theuluol, 1887-1981; ei ddyddiaduron, 1922-1981, a rhai ei dad, Joshua, 1893-1944; cofnodion Cylchdaith Annibynnwyr De Morgannwg, 1841-1978, Capel Siloh, 1850-1977, Eisteddfod Genedlaethol 1932 a 1948 ac eraill, 1932-1981; papurau Lewis Davies, Y Cymer (1863-1951), awdur nofelau i blant, [1849?]-1946, yn cynnwys sawl llyfr rent o Benderyn; papurau, 1883-1925, Rhys Dafydd Morgan (1851-1934), cyfieithydd o Gymro a fferyllydd ym Maesteg; papurau, 1882-1968, 'Wil Ifan' William Evans (1882-1968), archdderwydd, gweinidog yr Annibynwyr ac awdur; a phapurau, 1929-1979, 'Trefin, Edgar Phillips (1889-1962), bardd ac archdderwydd. = Papers concerning a wide variety of Brinli's activities including school books and other educational material, 1915-1977; legal papers, mainly correspondence and notes, 1918-1980; Maesteg Urban District Council records, 1927-1976; the Welsh Congregational Union papers, 1931-1976; local history, 1927-1971; the National Museum of Wales, 1976-1981; material relating to his books on Iolo Morganwg, [1974]-[1979]; the National Eisteddfod, 1926-1981, and eisteddfod adjudications, 1943-1981; newspaper cuttings, 1920-1980; Brinli's prose, 1919-1978, and poetry, 1932-1981; other literary works by him and others, 1913-1978; personal correspondence, 1909-1981; other personal and family papers, 1887-1981; his diaries, 1922-1981, and those of his father, Joshua, 1893-1944; records of the South Glamorgan Congregational Circuit, 1841-1978, Siloh Chapel, 1850-1977, and of the National Eisteddfodau of 1932 and 1948 and others, 1932-1981; papers of Lewis Davies, Y Cymer (1863-1951), author of children's novels, 1849-1946, including several rate books for Penderyn; papers, 1883-1925, of Rhys Dafydd Morgan (1851-1934), Welsh translator and Maesteg pharmacist; papers, 1882-1968, of 'Wil Ifan', William Evans (1882-1968), archdruid, congregational minister and author; and papers, 1929-1975, of 'Trefin', Edgar Phillips (1889-1962), poet and archdruid.

Three notebooks containing addresses given at eisteddfodau, meetings of Gorsedd y Beirdd, etc.; Welsh poetry; and various notes.
They include notes on Bardism, the outline of an address on 'John Elias o Fôn', and copies of the programme for the Llandudno National Eisteddfod, 1864, and The Literature of Wales, Reprinted from the Eclectic Review, ed. by Thomas Price (NLW MS 5758A); an address and other notes for the Denbigh National Eisteddfod, 1882 (NLW MS 5759A); and notes on Bishop William Morgan (NLW MS 5760A).

Papurau T. H. Parry-Williams yn ymwneud â'i addysg brifysgol ac fel athro, 1905-1960, teithiau i Dde a Gogledd America, 1925 a 1935, llythyrau oddi wrth deulu, cyfeillion ac amrywiol lenorion, academyddion ac ysgolheigion o Gymru ac Ewrop, 1908-1973, barddoniaeth wedi'i threfnu yn ôl ei ffurf, 1912-1954, ysgrifau,1937-1987, cyfieithiadau ysgrifau, 1987, beirniadaethau eisteddfodol, 1941-1971, darlithiau ac anerchiadau, 1917-1968, sgyrsiau a sgriptiau radio a theledu, 1933-1985, nodiadau ar dafodieithoedd ac enwau lleoedd, 1919-1935, geiriau Cymraeg i gerddoriaeth, 1929-1979, papurau'n ymwneud â'i waith cyhoeddus, 1916-1972, tystysgrifau, anrhydeddau a phersonalia, 1904-1960, cyhoeddiadau, adolygiadau llyfrau a thorion o'r wasg, 1928-1982, deunydd cyhoeddedig, 1865-1975, ac amrywiol, 1919-1994. Hefyd papurau Amy Parry Williams, 1910-1987, yn cynnwys gohebiaeth, 1948-1987, rhaglenni radio a theledu, caneuon gwerin a cherdd dant, storïau, ysgrifau a dramâu, a phapurau'n ymwneud â HTV, ymddiriedolaethau a phwyllgorau. Yn ogystal, papurau Henry Parry-Williams (1858-1925), tad T. H. Parry Williams yn cynnwys gohebiaeth, 1884-1920, barddoniaeth a rhyddiaith, 1891-1917, papur yn ymwneud â Robert R. Williams, Rhyd-ddu, 1876-1973 a Chanolfan Rhyd-ddu, 1972-1979 = Papers of T. H. Parry-Williams relating to his university education and teaching, 1905-1960, travels to South and North America, 1925 and 1935, letters from family, friends and various Welsh and European writers, academics and scholars, 1908-1973, poetry arranged by form, 1912-1954, essays, 1937-1987, translations of essays, 1987, eisteddfodic adjudications, 1941-1971, lectures and talks, 1917-1968, radio and television talks and scripts, 1933-1985, notes on dialects and local names, 1919-1935, Welsh lyrics for music, 1929-1979, papers relating to his public work, 1916-1972, certificates, honours and personalia, 1904-1960, publications, book reviews and press cuttings, 1928-1982, published material, 1865-1975, and miscellaneous, 1919-1994. Also Amy Parry Williams' papers, 1910-1987, including correspondence, 1948-1987, radio and television programmes, folk songs and cerdd dant, stories, writings and drama, and papers relating to HTV, trusts and committees. And also papers of Henry Parry-Williams, (1858-1925) father of T. H. Parry-Williams including correspondence, 1884-1920, poetry and prose, 1891-1917, paper relating to Robert R. Williams, Rhyd-ddu, 1876-1973 and Canolfan Rhyd-ddu, 1972-1979.

Papurau O. Llew Owain, 1785-[c. 1955], yn cynnwys llythyrau a phapurau yn ymwneud yn bennaf ag Eisteddfod Genedlaethol Cymru, Eisteddfod yr Urdd, a Gorsedd Beirdd Ynys Prydain, 1901-1951; ceisiadau am swyddi, 1939-1947; gweithiau Owain Llew Owain, 1912-1951; deunydd ar gyfer Y Genedl, 1924-1939; llythyrau, llyfrynnau a thorion amrywiol yn ymwneud ag agweddau ar fywyd a llenyddiaeth Gogledd Cymru, 1858-1950; llyfrau lloffion o dorion papur newydd, 1865-1940, yn cynnwys caneuon etholiadol, am David Lloyd George yn bennaf, teyrngedau i Syr John Morris Jones, torion o Y Genedl ac eitemau yn ymwneud â barddoniaeth Gymraeg; llawysgrifau a phapurau, 1785-[c.1955], o lyfrgell O. Llew Owain, yn cynnwys traethodau eisteddfodol ac arall, llawysgrifau o ddiddordeb i sir Gaernarfon a gohebiaeth. = Papers of O. Llew Owain, 1785-[c. 1955], comprising letters and papers mainly concerning Eisteddfod Genedlaethol Cymru (National Eisteddfod), Eisteddfod yr Urdd, and Gorsedd Beirdd Ynys Prydain, 1901-1954; job applications, 1939-1947; works of Owain Llew Owain, 1912-1951; material for Y Genedl, 1924-1939; miscellaneous letters, booklets and cuttings concerning aspects of North Wales life and literature, 1858-1950; scrap books of press cuttings, 1865-1940, including election songs mainly about David Lloyd George, tributes to Sir John Morris Jones, cuttings from Y Genedl and items relating to Welsh poetry; manuscripts and papers, 1785-[c. 1955], from the library of O. Llew Owain, including eisteddfod and other essays, manuscripts of Caernarfonshire interest and correspondence.