Duchess of Curiosities

Lady Margaret Cavendish Holles Harley, Duchess of Portland, amassed one of the largest and most remarkable natural history collections, known as The Portland Museum.

Margaret, also known as Peggy, was born on 11 February 1715. The only surviving child of Robert Harley's son, Edward Harley, second Earl of Oxford (1689-1741) and Lady Henrietta Cavendish Holles (1694-1755).

Portland's, Poets and Philosophers 

Peggy grew up surrounded by book lovers, scholars and poets. Not surprisingly, she came from a family of collectors: her grandfather, Robert Harley (1661 - 1724), Lord Treasurer and the first Earl of Oxford, was one of the great book and manuscript collectors of his day. 

Edward Harley inherited his father's titles, estates, book collection and his passion for collecting. He employed the architect James Gibbs to rebuild and extend Wimpole Hall, Norfolk, to house his growing collection, a project that dominated twenty years of Margaret's childhood. This fascinating art and book collection drew the attention of artists, writers and scholars, such as Alexander Pope, Jonathan Swift and Matthew Prior to Wimpole, as well as aristocrats and politicians. 

The poet Matthew Prior, a regular visitor, wrote a poem to her when she was only five: 

My noble, Lovely, little Peggy

Lett this my first Epistle beg ye

At dawn of Morn and close of Even

To Lift your Heart and Hands to Heaven:

In double Beauty Say Your Prayer

Our Father first, then Notre Pere

And, Dearest Child, along the Day 

In every thing you do or Say, 

Obey and please my Lord and Lady

So God shall Love, and Angels aid Ye

If to these precepts You attend, 

No second Letter need I send:

And so I rest, your constant Friend. 




As collectors, Lady Margaret's father and grandfather were impressive role models, but she also had a famous scientific ancestor on her mother's side: Margaret Cavendish, Duchess of Newcastle.

Born Margaret Lucas, she was the second wife of William Cavendish, First Duke of Newcastle, Lady Margaret's great-great-grandfather. A poet, philosopher, essayist and playwright, Margaret Cavendish wrote and published sixteen books with her husband's encouragement. Several, such as The Blazing World, were meditations on natural philosophy. The Duke was also a playwright, poet and patron of the arts. 


Sweet William 

Margaret married William Bentinck, Second Duke of Portland, on 11 June 1734 when she was 19 and he 25. In letters to friends, she called her husband affectionately 'True Blue' or 'Sweet William.' Soon after her marriage, she wrote to Katherine Collingwood, one of her closest friends, 

"I assure you that True Blue has every good quality you wished him to have", then writing again a few weeks later: The Sweet William's as agreeable as ever, and more so if possible; I wish you knew more of that flower, for I am sure you would be quite charmed by it; I assure you the Colly flower is a great favourite, and I don't doubt of its growing more so the better it is known. 

Her father, Edward Harley, died in 1741, and most of his art and book collection was sold. Lady Oxford Magaret's mother moved to her estate in Welbeck and dedicated herself to its renovation and landscaping until her death in 1755. 



Margaret and William made their home at Bulstroud Park, part of the Portland estate in Buckinghamshire. Here, she decided to use her wealth to build up her own collections and transform the house and gardens into a melancholy monument of Dutch magnificence. 

The Portland Museum 

During her lifetime, Margaret cultivated an enormous collection of natural history, which was tended by two experts she hired to personally attend each item: the naturalist Reverend John Lightfoot and the Swedish botanist Daniel Solander. Margaret archived her collection at Bulstroud Park, her London House. She shared her specimens with the public, displaying various collections from around the globe in what was known as The Portland Museum.

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


Miniature portrait of the Duchess of Portland, Christian Zincke, c1750. The Duchess is wearing jewellery, including a pearl pendant in the shape of a dolphin. The pearl was a gift from her father, who purchased it in 1720 for £50. The miniature was painted when the Duchess was 35 years old.  


Discover more about the history of Welbeck with a visit to The Portland Collection Museum