Manuscripts and Special Collections

Biography of Margaret Cavendish-Bentinck, Duchess of Portland (1715-1785)

Margaret Cavendish Harley was born in London, the only surviving child of Edward Harley, who was later 2nd Earl of Oxford, and his wife Henrietta, daughter of John Holles, 3rd Duke of Newcastle upon Tyne. She was a favourite of the literary circle surrounding the Harleys, for example having a poem addressed to her at the age of five by Matthew Prior.

After her marriage (through which a large proportion of Newcastle/Cavendish propety and papers passed into the Portland line of descent), Margaret actively pursued her interest in fine art and natural history, amassing the largest collection in Britain. Her passion for botany led to her friendships with plantsman, Philip Miller and botanical illustrator, Georg Dionysius, who produced many of his notable paintings of British plants for her. She had a special interest in sea shells, and kept bees and hares as well as maintaining an aviary and menagerie.

On Margaret's death in 1785 her huge collection of fine art and virtu was sold off. The sale took place in 1786 and lasted 38 days in total. Perhaps the most famous item which formed part of her collection was the so-called 'Portland Vase', now held by the British Museum.

An engraving of a bust of the Duchess of Portland, by George Vertue, after John Michael Rysbrack, is available on the National Portrait Gallery website.


In 1734 she married William, 2nd Duke of Portland and had:

  • William Henry Cavendish (1738-1809), later 3rd Duke of Portland
  • Edward Charles (1744-1819)
  • Elizabeth (1735-1825) m Thomas, 1st Marquess of Bath in 1759
  • Henrietta (1737-1827) m George, 5th Earl of Stamford in 1763
  • Margaret (1739-1756) died unmarried
  • Frances (1741-1743) died young

Archive Collections

Published Sources

Though there are no biographies dedicated exclusively to Margaret, details of her life appear in:

  • Turberville, A.S., A History of Welbeck Abbey and its Owners, Volume 2 (London, 1938) [King’s Meadow Campus East Midlands Collection Not 468.D14 TUR]

University Theses

Porter, Katherine H., Margaret, Duchess of Portland (Cornell University PhD Thesis, 1930)


Manuscripts and Special Collections

Kings Meadow Campus
Lenton Lane
Nottingham, NG7 2NR

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