The collection is largely composed of deeds, conveyances and administrative papers connected with the purchase and running of the Denison estates. It includes accounts, rentals, correspondence, surveys, maps and plans, including architectural records, but the bulk of the collection consists of deeds and abstracts of title. A small number of manorial records, dating back to the 17th century, are present for Sutton-on-Trent and Ossington. Family settlements and wills extend the scope of the archive, providing personal information about earlier holders of the properties, and overlapping in interest with the separate personal collections of family members.
There is extensive coverage of the Nottinghamshire estates, centring on Sutton-on-Trent, Ossington, Laxton, Norwell, Normanton-on-Trent, Carlton-on-Trent and Kelstern. Records from Laxton, which has continued to be managed on the open-field system, have particular interest. Other small series of property records come from Coatham [in Long Newton], Grindon [in Aycliffe] and Little Chilton in County Durham, Kelstern in Lincolnshire, and Rimswell and Beswick in the East Riding of Yorkshire.
The merchant origins of the Denison family of Leeds, Yorkshire are recorded in a number of records, including Wilkinson and Denison wills, accounts, and building and planning documents. Some of the papers concern railway, road and water transport developments.
The second accrual of papers (De 2) exclusively concerns architectural plans, 1775-1825. A number of these are copies of originals still in private hands. The majority of the plans are for the Ossington estate, but a few documents are present which appear to be unrelated to family properties, such as a copy of John Nash's plan to build a new street in London, 1811. The greater number of the Ossington plans are by William Lindley (c.1739-1818), who worked for the Denisons from the late 1780s until his death in 1818. His plans relate to the Hall itself, and to farm buildings and other domestic estate properties. The collection includes designs by John Carr (1723-1807) for a temple, church and mausoleum at Ossington, and copies of plans made for Ossington in 1786 by Sir John Soane (1753-1837).
The third accrual (De 3) is a single 17th century document, which provides a copy of an inspeximus grant of 1423 by Henry VI recognising the liberties of the order of St John of Jerusalem (Knights Hospitallers) in England.
The fourth accrual (De 4) relates to the affairs of the Wilkinsons and Denisons in the late 18th century and early nineteenth century, consisting mainly of wills, correspondence and property deeds. It includes papers relating to Leeds, and to the Aire and Calder Canal. A single estate map for Ossington, 1787, is also present.