The collection consists of notes on lectures on English language and literature, history and law made by R. T. Jenkins as a student at the University College of Aberystwyth and at Trinity College, Cambridge, 1898 - 1902. Also notes on medieval history made from 1907 onwards.
There are lectures and lecture notes by R. T. Jenkins on Welsh history held at the University College of North Wales; and occasional lectures, addresses and papers, ca 1940 - 1961 on various subjects relating to Welsh history and historical figures.
The articles and broadcasts date from 1949 - 1965, whilst the articles and printed material date from 1911 - 1962.
Sixteen notebooks contain notes and jottings on various aspects of Welsh history in which R. T. Jenkins was interested and which were apparently compiled by him in preparation for writing his major historical works.
The files of notes and references also cover various subjects such as Wales and the drovers and Moravianism in Wales, ca 1931 - ca 1949.
There are papers relating to The Dictionary of Welsh Biography, 1940 - 1965; letters to R. T. Jenkins, 1929 - 1965 and miscellaneous material such as a memorial lecture by Sir J. E. Lloyd enclosing a letter to R. T. Jenkins, 1928 from him.