Papers, lecture and research notes of and acquired by Mary Williams, relating to Middle French, Middle Welsh and medieval literature and Arthurian studies, 1907-1963; books collected by Mary Williams, 1897-1911; letters to Prof. Victor Spiers, 1898-1916; vouchers and receipts, 1924-1973; newspaper cuttings, 1911-1940; school books 1909-1916; papers relating to University College Swansea, 1921-1975, University of Wales Aberystwyth, 1924-1974, University of Durham, 1948-1952, and National Library of Wales, 1941-1974; correspondence, 1927-1976; and family papers, 1898-1944.