Elizabeth Percy, Duchess of Northumberland

For other people of the same name, see Elizabeth Percy (disambiguation).

Elizabeth Percy, née Seymour, Duchess of Northumberland, heiress to the earldom of Northumberland and 2nd Baroness Percy (26 November 1716 – 5 December 1776) was a British peeress.

Elizabeth was the only daughter of the 7th Duke of Somerset and his wife, Frances, a daughter of Henry Thynne. On 16 July 1740, she married Sir Hugh Smithson, Bt and they had two sons, Hugh (1742-1817) and Algernon (1750-1830). On her father's death in 1750, she inherited his barony of Percy and her husband acquired from her father his earldom of Northumberland by special remainder and changed his family name from Smithson to Percy that year. Sir Hugh's illegitimate son James Smithson, otherwise Jacques Louis Macie, born in about 1764 to one of Elizabeth's cousins, bequeathed the fortune which established the Smithsonian Institution.

In 1761, Elizabeth became a Lady of the Bedchamber to Queen Charlotte, a post she held until 1770. She became a duchess in 1766 when her husband was created Duke of Northumberland, and on her death in 1776 her barony and the Earldom of Northumberland passed to her eldest son, Hugh, who inherited his father's dukedom ten years later. He built Brizlee Tower as one of a number of monuments to commemorate her.

Ancestors of Elizabeth Percy, Duchess of Northumberland