Nottingham Castle was set on fire by rioters on 10 October 1832.
The principal manuscript collection is the Newcastle of Clumber Collection, containing the principal family archive (personal, political, estate and domestic correspondence, account books, ledgers, maps, rentals and diaries). The collection has been held by the Department of Manuscripts and Special Collections, University of Nottingham, since 1955 (when the first deposit was made). It was accepted in lieu of estate duty in 1981 and has continued to receive accessions ever since. It has been extensively catalogued in recent years. See: www.nottingham.ac.uk/ (under 'Family Collections'). The department has issued two leaflets of interest to researchers: Political and Personal Papers of the Dukes of Newcastle and Estate Collections of the Dukes of Newcastle which provide further information on the collection.
The University of Nottingham's Hallward Library holds the Gladstone Papers on Microfilm. This edition, which is available for reference only, includes the correspondence between Newcastle and W E Gladstone (British Library Additional MS 44261 ff.1-115).
Other manuscript collections relating to the fourth duke of Newcastle-under-Lyne may be located via the search facilities in Access to Archives. See: www.a2a.org.uk