Bentinck family, Earls of Portland

Hans Willem Bentinck (1649-1709) came to England from the Netherlands and was created Earl of Portland in 1689 by his close friend William III. He acquired a number of estates including Bulstrode in Buckinghamshire; Theobalds in Hertfordshire; and properties in Cumberland and Soho, Middlesex. His son, Henry (1682-1726), who was created 1st Duke of Portland in 1716, married Elizabeth Noel, daughter of the 2nd Earl of Gainsborough, and through her acquired the Titchfield estates in Hampshire (formerly owned by the Wriothesley family, Earls of Southampton). It was through the marriage of their son Henry, 2nd Duke (1709-1762) to Lady Margaret Cavendish Harley (1715-1785) in 1734 that the former Cavendish-owned Welbeck estates in Nottinghamshire came into the possession of the Bentinck family, Dukes of Portland.

Lady Margaret Cavendish Harley was the daughter and heir of Edward Harley, 2nd Earl of Oxford (1689-1741), and his wife Henrietta (1694-1755), the daughter of John Holles, 3rd Duke of Newcastle upon Tyne (d 1711) and Margaret Cavendish, who was the daughter and heir of Henry Cavendish, 2nd Duke of Newcastle upon Tyne (d 1691). Through her mother and grandmother Lady Margaret inherited not only the Welbeck estates but also many of the family papers of her Harley/Holles and Cavendish forebears. These were inherited on her death by her son William Bentinck, 3rd Duke of Portland (1738-1809) who made Welbeck Abbey his principal seat.

Papers of nineteenth-century members of the family also form part of the collection. These include the extensive official and administrative papers of Lord William Bentinck, brother of the 4th Duke of Portland, covering his career in Sicily and India, and the papers of Viscountess Ossington, sister of the 5th Duke of Portland.

During the late eighteenth and early nineteenth century most of the Bentinck and many of the other inherited estates were sold as were the Balcomie (Scottish) estates, which had been brought into the family through the marriage of William, 4th Duke of Portland (1786-1854) to the heiress, Henrietta Scott.

Although referred to as the Portland Collection, the papers at Nottingham are not those described by J.J. Arkwright, Papers of the Dukes of Portland, 10 vols (Historical Manuscripts Commission, 1891-1931), which are now held in other repositories.