Francis Charles Seymour Conway (1777-1842), styled Viscount Beauchamp between 1793 and 1794 and Earl of Yarmouth between 1794 and 1822, became the 3rd Marquess of Hertford in 1822. In 1797 he married against his parents' wishes Maria Fagnani (also known as Mimi) the illegitimate daughter of the Marchesa Fagnani. She greatly increased the family's wealth through substantial bequests from the 4th Duke of Queensberry (Old Q) and George Selwyn. The 3rd Marquess had two children with his wife, a daughter Frances who died in 1822 and the future 4th Marquess Richard Seymour-Conway. In 1802 the 3rd Marquess and Maria Fagnani visited Paris, there they soon became estranged from one another and from that point led separate lives. She remained in Paris whilst the 4th Marquess returned to London establishing splendid residences in London at Dorchester House and at St Dunstan's Villa in Regent's Park (both of which have since been demolished). He also had a long career in politics serving almost consecutively as an MP from 1797 to 1822; in addition he served as Vice-Chamberlain in the Royal Household between 1812-1821. His later life was largely devoted to dissipation and foreign travel to such an extent that the sinister Lord Steyne in Thackeray's 'Vanity Fair' was based on him. The 3rd Marquess was a considerable art connoisseur he purchased Titian's 'Perseus and Andromeda' and seventeenth century Dutch paintings such as Rembrandt's 'Good Samaritan', he also bought French furniture, gilt bronzes and Sèvres porcelain which are still in the collection. He also acted as salesroom agent for the Prince of Wales with whom he shared an interest in the collecting of French 18th century art.
These papers include correspondence, accounts and lists of items.