A Latin vocabulary, notes for the study of the Mabinogion, extracts from printed sources, notes on 'Y Gogynfeirdd' and their vocabulary, etc.

Two scrap-books, compiled by 'Golyddan', containing press cuttings of the controversy in Yr Amserau, 1851, on poetic metres between 'Ieuan Gwynedd' and 'Gweirydd ap Rhys', a controversy on music between 'Ap Musicus' and Edward Stephen ('Tanymarian'), and other cuttings of literary interest; and a scrap-book compiled by Catherine Prichard ('Buddug') containing literary press cuttings, including material relating to John Robert Pryse ('Golyddan'), with a draft letter by Robert John Pryse ('Gweirydd ap Rhys').

Addresses by Meredith J. Hughes on 'Myth and legend in the literature of Wales', 1914, and 'Democratic Theory and Institutions', 1919; a hymn 'Ymwel a mi o Arglwydd da', and a poem entitled 'Afon Alun', 1924.

Over a hundred letters, 1964-1980, from Aneirin Talfan Davies to Katharine Taylor Loesch, University of Illinois, Chicago, relating mainly to personal matters but also containing references to his work and to Welsh and English literature.

Manuscripts, estate records and papers of the Wynne family of Bodewryd, Anglesey, including records of the Bodowyr estate (Bodedern), Anglesey, and Plas Einion estate, Denbighshire, and papers of the Owen family of Penrhos, Anglesey; important Welsh literary manuscripts, legal manuscripts relating to civil and ecclesiastical law; the antiquarian collections of Edward Wynne, chancellor of Hereford, relating to Wales and to the diocese of Hereford, and part of the collection of Humphrey Humphreys, bishop of Bangor and later of Hereford; letters to Humphrey Humphreys, 1691-1709 (mainly 1705-1709); Wynne family correspondence, 1613-1816; legal papers, [17 cent.]-[18 cent.], especially relating to a lengthy action between Chancellor Edward Wynne and the Mostyn estate following the purchase by Wynne of the Bodowyr estate, 1721-1746; estate, personal and household accounts, 1603-1753; and title deeds, [13 cent.]-1864.

Press cuttings relating to Wales and Welsh culture, such as religion, politics, literature, music, education, St. David's Day celebrations and the Eisteddfod Genedlaethol, individuals, and the National Library of Wales [1895]-[1939].

Articles and addresses by David Samuel mainly on Welsh literature, history and education, 1890-1909, and an account of his tour in the United States of America, 1889.

Some three hundred and fifty letters, 1945-1969, from Gilbert Turner to John Cowper Powys and Phyllis Playter, which include references to the novelist Elena Puw Morgan, Welsh language and literature, visits to North Wales, the writer's procurement of library books for the recipients and the preparation of typescript copies of Powys's Dostoievsky (1947) and Rabelais (1948). Turner continued corresponding with Phyllis Playter after John Cowper Powys's death in 1963.

An account of the early history of Wales and notes on Welsh place-names, literature, etc.

Manuscripts and papers of Iolo Morganwg and Taliesin ab Iolo, [16 cent.]-[20 cent., first ¼], comprising correspondence of Iolo Morganwg, 1676-1826; manuscripts and other papers, [16 cent.]-1900, mostly collected or written by Iolo Morganwg, including Welsh and English poetry and prose, pedigrees, grammars, and other literary and personal papers; correspondence, 1809-1864, and other papers, 1761-[1840s], of Taliesin ab Iolo; and family correspondence of Taliesin's grandson, Aneurin Williams, [?1868]-1908.

Drafts and notes in the hand of Taliesin Williams for the volume Iolo Manuscripts, A Selection of Ancient Welsh Manuscripts, in prose and verse, from the collection made by the late Edward Williams, Iolo Morganwg,… with English translations and notes by his son, the late Taliesin Williams (Ab Iolo) of Merthyr Tydfil (Liverpool: Welsh MSS Society, 1848).
Included are manuscript drafts of the Welsh texts on pp. 3-328 passim (T4/1), drafts of the English translations on pp. 341-496 passim (T4/2), drafts for the footnotes on pp. 332-489 passim (T4/3), a draft of pp. 331-507 passim combining text and footnotes (T4/4), and notebooks containing notes and memoranda relating to the volume (T4/5-11). Also included is a bundle of draft texts, relating mostly to Welsh saints in a format similar to T4/1 but which were either omitted from the volume or intended for another book on Bonedd y Saint (T4/12).

A manuscript containing a transcript of a lecture on The Influence of the Literature of Wales on that of other countries, given by Teilo at Llandilo, 16 March 1864; a note on Thomas Jones (Twm Sion Catti); material relating to the late Rev. John Evans, Llwynffortun, 1865.

A letter, 1855, from John Williams ('Ab Ithel') to [Evan Davies ('Myfyr Morganwg')].

Autograph letters, mainly relating to English and Welsh literature and scholarship, the correspondents including John Blackwell ('Alun'), Henry Bradshaw, Lady Eleanor Butler, Sir John Hanmer, A. Hayward, W. Walsham How, Arthur James Johnes, John Jones ('Idrisyn'), W. Basil Jones, R. Harries Jones, Benjamin Hall Kennedy, Max Muller, Alfred Ollivant, Sir John Rhys, Thomas Rowland (author of A Grammar of the Welsh Language), A. H. Sayce, T. Vowler Short, Connop Thirlwall, T. F. Tout and Albert Way; with a number of 'cut-out' autographs.

Autograph letters from a large number of people to Thomas and others, mainly relating to archaeology, Welsh history, literature and ecclesiastical affairs. The correspondents include B. Beedham, William Buckland, W. Boyd Dawkins, Walter Davies ('Gwallter Mechain'), J. P. Earwaker, D. Silvan Evans, R. W. Eyton, E. A. Freeman, Margaret Gatty, Reginald Heber, Felicia Hemans, H. Longueville Jones, John Keble, Sir Theodore Martin, Sydney (Lady) Morgan, Lord Mostyn, Samuel Rogers, W. F. Skene, Sir Arthur Sullivan, John Williams ('Ab Ithel'), Morris Williams ('Nicander') and Robert Williams (Rhydycroesau); an English poem entitled 'The Sixth Centenary of Dante's Beatrice 1890' by T. Tudno Jones; and a number of 'cut-out' autographs.

Nearly two hundred autograph letters, 1855-1891, relating mainly to Welsh literary matters, and especially to Glamorgan, 1855-1899, to Jonathan Reynolds ('Nathan Dyfed') from contemporary Welsh poets and authors; miscellaneous poems; printed broadsides; press cuttings; etc.

Literary papers from various sources.

'Casgliad Cyflawn o Lên Gwerin Cymru wedi eu cynull o Lyfrau Argraphedig Cymraeg (gan eithrio Y Mabinogion) hyd ymddangosiad Y Brython', written for the National Eisteddfod of Wales held at Liverpool, 1900.

Letters, 1835-1840, from David Owen ('Dewi Wyn o Eifion') to Richard Humphreys (Faerdref) , Ellis Owen and James Spooner (Tremadog), together with drafts of letters by David Owen relating to Welsh literary matters.

Miscellaneous notes by Walter Davies relating mainly to Welsh literature, history, and archaeology.