The Mellish papers comprise a substantial family and estate archive, being for the most part records about their North Nottinghamshire estates during the period of the family's ownership. In addition there are some survivals from their merchant origins in London and a number of significant medieval records inherited through property acquisiton.
The collection includes a large number of property deeds, wills and abstracts of title (early 12th century-1803) relating mostly to North Nottinghamshire and Yorkshire, but other counties are also represented. These are supported by a substantial body of estate papers and related correspondence, 1523-1863, providing further details about the exchange and ownership of lands and also about the administration of the estates. There is a considerable amount of material from the Mellish Yorkshire estates (papers from the Manor of Tickhill c.1600-1639 are a notable example) as well as those in Nottinghamshire. The latter includes material from the Manor of Blyth.
Unfortunately, no run of estate maps or surveys has survived, although some maps and surveys are to be found scattered throughout the bundles of estate papers, including a survey of the land purchased from Sir Gervase Clifton in 1765.
An extensive body of accounting material from 1648 to 1863 includes a range of different forms of estate, household, business and personal accounts, none of them in a long series. Estate rentals have patchy coverage, but are supplemented by farm cash books. There are two household account books (1784-1816). Some business accounts have been separately listed, 1613-1839.
Thirty-eight bundles of correspondence (1683-1853) cover estate, family and personal, business and social interests. They include letters from prominent members of the family such as Edward Mellish of Blyth Hall (1633-1703), Joseph Mellish (1675-1733), William Mellish (1708-1791) and Charles Mellish (1737-1797). Correspondence includes references to families linked by marriage, particularly the Baker, Gore, Gardner and Chambers families. Other personal letters contain extensive references to the education of the children, including correspondence between Charles Mellish and his son Joseph from 1779.
Business correspondence includes several letter books from the seventeenth century, and evidence of the continued connection of the family with mercantile and professional legal interests. In connection with the family's own business interests, a considerable number of letters relate to the navigation of the River Dun [Don].
The letters of Charles Mellish provide comment and detail about political events and include letters from General Sir Henry Clinton and others concerning the American War of Independence. Foreign matters are also found in a number of journals and travel diaries covering Europe and the Near East, 1621-c.1852. It is not always clear why these journals are present in the family papers. There is for example no obvious explanation for the presence of a copy of a journal relating to the shipwreck of the East Indiaman 'Doddington' and the escape of its crew from Bird Island, 1755-1756.
Legal works from 1587 to the late 18th century include both texts apparently used in the practice of law and documents resulting from legal process.
A series of literary, antiquarian, religious and philosophical papers, together with some genealogical material and printed papers, are also present. Many of these papers were collected by Charles Mellish in the course of his antiquarian studies.
The collection also includes the 15th century 'Rushall Psalter'. Vernacular sections within the volume include items by Lydgate and Chaucer and an account of the Rushall family from the conquest. See J.W. Whiston 'The Rushall Psalter', appendix to N.J. Baker, 'The gatehouse of Rushall hall, Staffs.' in 'Transactions of South Staffordshire Archaeological and Historical Society vol.xxiii (1983) pp 89-91.
An additional deposit of medieval deeds relating to the Priories of Earls Colne and Hatfield, Essex (Me 3) also includes a stray letter of Napoleon Bonaparte to M. L'Abbé Raynal dated 1790.
A further deposit comprises letters from various members of the Mellish family, including Henry Francis Mellish during the Peninsular Campaign, correspondence of George Samuel Mellish in India, and abstracted correspondence of Edward Mellish 1660-1670. There are also deeds, estate papers, a collection of antiquarian and genealogical notes, and a printed pamphlet collection belonging to Henry Mellish.