Collection comprises correspondence with Philip Hammersley Leathes, manuscript papers, diaries, devotionals, dictionaries and pedigree rolls, title deeds and indentures, printed books and pamphlets, catalogues and the manuscripts of the architect, John Carter, [1350-1863]. Notably including correspondence from George Nayler of the College of Arms and Nicholas Carlisle, Secretary of the Society of Antiquaries, relating to publications of the Society, discoveries of antique brass plate, and the exchange of manuscripts between antiquaries, [1790-1838]; loose manuscript papers collected by Leathes, describing ornamentation in early printed devotionals, a fictional narrative entitled 'The amorous Jill: A tale', narrative of the Lisbon earthquake of 1755, notes relating to the observation of comets, including the comet of 1811, copies of charters of the reigns of Edward IV and Henry VII, papers relating to the Portland Vase, British Museum, fragments describing inscription on newly discovered brass plate, 1747-1829; pedigree rolls tracing the lineage of the English Crown, [1450, 1762]; manuscript volumes including collection of biblical extracts, liturgical handbook, autograph book with colour illustrations, antiquarian ephemera such as funeral memorials, armorials and the creation of nobles, volume by Francis Harrison entitled, 'The elements of navigation' with colour charts, tables and illustrations, dictionaries of Celtic and Saxon words, notes on the teaching of mathematics, commonplace book drawing on ancient and modern authors, manuscript diary including progress of architectural tour of Europe; title deeds and indentures for families in Nottingham, Southampton, London and Hungerford, residency certificates in Buckinghamshire and Northamptonshire, 1650-1751; printed books and pamphlets on the subjects of antiquarianism, genealogy and architecture, 1778-1853; manuscripts of John Carter, architect, acquired at his death in 1817 by his executor, Leathes, notably including autobiographical notebooks by Carter describing architectural subjects and tours, commonplace book, correspondence with Leathes, loose notes on linguistics and the ships of the Russia Company, obituaries of Carter and sale catalogue from his estate, 1700-1818; manuscript catalogues and display captions relating to the Leathes' papers, King's College London, 1819, 1837.

Papers relating to his life and career, 1935-1982, dated 1911-1982, principally comprising administrative papers relating to his Army career, 1938-1971, including postings in India, Iraq, Persia, Egypt, Cyprus and Singapore; papers relating to his attendance at the 'Buffalo' British nuclear weapons tests, Maralinga, Australia, 1956; course syllabuses, lecture summaries andassociated papers, [1935-1966], notably concerning tropical medicine, entomology, public health, malaria and encephalitis; unsigned report, photographs and other papers relating to flood relief operation, Vientiane, Laos, Sep 1966; photographs, 1942-1961, mainly relating to his service in Malaya, 1958-1961; official War Office and Government of India publications concerning army regulations, training and health and medical services; Bulletins of the Ross Institute, School of Hygiene and Tropical Medicine, University of London, 1956, 1959-1962; personal and family correspondence, 1938-1982.