Papurau Eifion Wyn yn cynnwys copïau llawysgrif o'i gerddi, 1885-1925, rhai ohonynt wedi eu cyhoeddi yn Caniadau'r Allt (1927) ac O Drum i Draeth (1929); ei gyfieithiadau o farddoniaeth a rhyddiaith, 1906-1923; pregethau, emynau a chaneuon, [c.1914]-1921; cerddi gan eraill, 1889-1926; beirniadaethau cystadlaethau eisteddfodol, 1915-1925; llythyrau a gohebiaeth â llenorion, 1894-1926; llythyrau at ei wraig, 1922-1950; cofnodion cofrestru aelodau'r teulu, 1864-1941; tystysgrifau eisteddfodol, 1905-1924; deunydd printiedig,1908-1927; llyfrau, yn cynnwys gwaith gan Eifion Wyn, 1866-1930; dyddiaduron Eifion Wyn, 1919-1920; dyddiaduron ei dad Robert Williams, 1894-1900; a phapurau'n perthyn i'w ŵyr Penri Williams, 1926-[1980] = Papers of Eifion Wyn comprising manuscript copies of his poems, 1885-1925, some of which were published in Caniadau'r Allt (1927) and O Drum i Draeth (1929); translations by him of poetry and prose, 1906-1923; sermons, hymns and songs, [c. 1914]-1921; translations of his poetry by others, 1907-1924; poems addressed to him, 1919-1921; poems by others, 1889-1926; adjudications of eisteddfod competitions, 1915-1925; letters and correspondence with literary figures, 1894-1926; letters to his wife, 1922-1950; family civil registration records, 1864-1941; eisteddfod certificates, 1905-1924; printed matter, 1908-1927; books, including Eifion Wyn's works, 1866-1930; diaries of Eifion Wyn, 1919-1920, diaries of his father Robert Williams, 1894-1900; and papers belonging to his grandson Penri Williams, 1926-[1980].

Papurau T. Gwynn Jones, 1871-1949, yn cynnwys: gohebiaeth, gan gynnwys llythyrau oddi wrth amrywiaeth eang o ffigurau llenyddol ac academaidd; cerddi a phapurau llenyddol eraill, yn cynnwys adysgrifau ac arnodiadau gan T. Gwynn Jones o waith gan awduron canoloesol a modern, a deunydd, [17 gan.]-[20 gan.], a gasglwyd ganddo neu a roddwyd iddo; papurau academaidd, yn cynnwys nodiadau ar gyfer ei lyfrau ac erthyglau, cofiannau a mynegeion i'w waith ei hun a gwaith pobl eraill, a nodiadau bywgraffyddol ar lawer o ffigurau llenyddol; cyfieithiadau; darlithoedd ac anerchiadau, yn cynnwys nodiadau; sgriptiau radio; adolygiadau llyfrau; gwahanlithiau; torion o'r wasg; dramâu, beirniadaethau eisteddfodol, deunydd yn ymwneud â'i Dysteb yn 1944; llongyfarchiadau ar ei CBE yn 1937; a dyddiaduron, 1927-1947, a phersonalia arall; ceir hefyd papurau teuluol, 1621-1871, gan gynnwys gohebiaeth, dau Feibl teuluol, a llythyrau, 1949-1985, at deulu Jones, yn ymwneud yn enwedig â'i fywyd a'i waith, a chofiannau iddo. = Papers of T. Gwynn Jones, 1871-1949, comprising: correspondence, including letters from a wide variety of literary and academic figures; poems and other literary papers, including transcripts and annotations by T. Gwynn Jones of works by medieval and modern authors, and material, [17 cent.]-[20 cent.], collected by him or given to him; academic papers, including notes for his books and articles, bibliographies and indexes for his own and other works, and biographical notes on many literary figures; translations; lectures and addresses, including notes; radio scripts; book reviews; offprints; press cuttings; plays; eisteddfod adjudications; material relating to his Testimonial in 1944; congratulations on his CBE in 1937; and diaries, 1927-1947, and other personalia; also included are family papers, 1621-1871, including correspondence, two family bibles, and letters, 1949-1985, to Jones's family, especially concerning his life and work, and memorials to him.

Papurau'r Parch James Ednyfed Rhys (Ap Nathan), a phapurau'r unigolion canlynol a ddaeth i'w feddiant: y Parch. Evan Rees (Dyfed), Jonathan Rees (Nathan Wyn), David Watkin Jones (Dafydd Morganwg) a Thomas Jones, Trealaw. Mae papurau Ap Nathan, 1901-1959, yn cynnwys cerddi a chaneuon, ysgrifau a chyfieithiadau; papurau Dyfed, 1869-1923, yn cynnwys llythyrau, nifer ohonynt o bwysigion llenyddiaeth Cymru, 1878-1923, dyddiaduron a llyfrau poced, 1873-1896, beirniadaethau eisteddfodau, 1887-1907, nodiadau darlithoedd a phregethau, a barddoniaeth, 1869-1899; papurau Nathan Wyn, 1874-1905, yn cynnwys llythyrau, 1874-1905, cerddi ac ysgrifau, 1883-1901, torion o'r wasg ar bynciau llenyddol, 1868-1900; papurau Thomas Thomas, 1900-[c. 1935], yn cynnwys llawysgrifau ar lên gwerin ac arferion, hanes Morgannwg, 1921-1933, y Wenhwyseg, enwau lleoedd Morgannwg, [c. 1893]-1931, a thorion o'r wasg, 1900-1911; a phapurau Dafydd Morganwg, yn cynnwys ei hunangofiant. = Papers of the Rev. James Ednyfed Rhys (Ap Nathan), and papers of the following acquired by him: the Rev. Evan Rees (Dyfed), Jonathan Rees (Nathan Wyn), David Watkin Jones (Dafydd Morganwg), a poet and historian from Merthyr Tydfil, Glamorgan, and Thomas Jones, antiquary and headmaster of Trealaw school in Rhondda, Glamorgan, whose interests included local history and folklore. The papers of Ap Nathan, 1901-1959, include poems and songs, essays and translations; the papers of Dyfed, 1869-1923, include letters, many from important Welsh literary figures, 1878-1923, diaries and pocket books, 1873-1896, eisteddfod adjudications, 1887-1907, lecture notes and sermons, and poetry, 1869-1899; the papers of Nathan Wyn, 1874-1905, include letters, 1874-1905, poetry and essays, 1883-1901, newspaper cuttings of literary material, 1868-1900; the papers of Thomas Jones, 1900-[c. 1935], include manuscripts on folklore and customs, Glamorgan history, 1921-1933, the Gwentian dialect, Glamorgan place names, [c. 1893]-1931, and newspaper cuttings, 1900-1911; and the papers of Dafydd Morganwg, historian and poet, including his autobiography.