Papers of the Rev. C. Tawelfryn Thomas, 1837-1938, comprising letters addressed to him from religious, literary and political figures, 1874-1938, mainly about biographical details of historical and contemporary ministers and poets, eisteddfod competitions, publication of books and articles, including Thomas's own work on Ieuan Gwynedd, the Independent College in Bala, personal matters, preaching engagements and ministers' appointments; stanzas composed by him; and poetry by William Cosslett (Gwilym Elian) and others, 1837-1903.

Papurau o eiddo J. Dyfnallt Owen neu a grynhowyd ganddo, 1863-1956, yn cynnwys pregethau; nodiadau bywgraffyddol ar weinidogion anghydffurfiol; llythyrau a phapurau eraill yn ymwneud ag achos yr Annibynwyr, 1863-1953; llythyrau amrywiol pellach, 1878-1956, rhai ohonynt yn cyfeirio at yr Orsedd yn Llydaw a Chernyw; dyddiaduron, 1897-1956; cyfraniadau ar gyfer eu cyhoeddi yn Y Tyst, etc., 1923-[1953]; sgriptiau radio, 1931-1955; pregethau, 1919; torion o'r wasg, [1872]-1954; dyddlyfrau taith, a nodiadau ar bynciau hanesyddol a llenyddol, 1901-1953. = Papers of and accumulated by J. Dyfnallt Owen, 1863-1956, including sermons; biographical notes on nonconformist ministers; letters and other papers concerning the Independent cause, 1863-1953; further miscellaneous letters, 1878-1956, some of which refer to the Gorsedd in Brittany and Cornwall; diaries, 1897-1956; contributions for publication in Y Tyst, etc., 1923-[1953]; radio scripts, 1931-1955; sermons, 1919; press cuttings, [1872]-1954; travel journals, and notes on historical and literary subjects, 1901-1953.