Papers of and relating to Sir Daniel Lleufer Thomas, 1599-1941, comprising general correspondence of Sir Daniel Lleufer Thomas, 1893-1919 and 1922-1940; general correspondence of Lady Thomas, 1895-1941; American letters from descendants of relatives who emigrated, 1873-1931; letters of Welsh interest mainly concerning localities and place-names, 1892-1919; letters relating to T.E. Ellis, 1898-1935; personal letters and cards from Daniel Lleufer Thomas to his wife, 1902; political letters, 1906-1933; papers relating to Daniel Lleufer Thomas's legal career and interests, 1891-1938; subject files relating to his public offices, including his appointment to the Welsh Land Commission, 1887-1941, societies and institutions to which he belonged, 1886-1940, Llandovery School, 1880-1935, the translator and poet Richard Morris Lewis, 1866-1933, general literary and historical interests, 1889-1940, and miscellaneous subjects, 1915-1933; and personal papers which include deeds of Brynmaen, once the family home, 1599-1885, and diaries of Daniel Lleufer Thomas and Lady Thomas, 1892-1899.