| Honorific Prefix: | Her Grace |
| The Duchess of Cleveland | |
| Birth Name: | Lady Catherine Lucy Wilhelmina Stanhope |
| Birth Date: | 1 June 1819 |
| Birth Place: | Mayfair, England |
| Death Place: | Wiesbaden, Hesse, Germany |
| Othername: | Lady Dalmeny Lady Harry Vane |
| Occupation: | Historian, genealogist |
| Children: | Archibald Primrose, 5th Earl of Rosebery |
| Parents: | Philip Henry Stanhope, 4th Earl Stanhope Hon. Catherine Lucy Smith |
Catherine Lucy Wilhelmina Powlett, Duchess of Cleveland (née Stanhope; 1 June 1819 - 18 May 1901), also known as Lady Dalmeny and Lady Harry Vane, was an English courtier, historian and genealogist, best known for her 1889 work The Battle Abbey Roll with some Account of the Norman Lineages.
By her first marriage to Lord Dalmeny, she was the mother of Prime Minister Archibald Primrose, 5th Earl of Rosebery.[1]
Lady Wilhelmina Stanhope was born in Mayfair, the third child and only daughter of Philip Henry Stanhope, 4th Earl Stanhope (1781-1855), FRS, and his wife, Hon. Catherine Lucy Smith, daughter of Robert Smith, 1st Baron Carrington.[2] She was known as Wilhelmina to distinguish her from her mother.
At the time of Queen Victoria's accession, the 18-year-old Lady Wilhelmina was regarded as one of the most beautiful woman at court. She was a train-bearer at the queen's coronation in 1838, and served as a bridesmaid at her wedding to Prince Albert in 1840.[1]
Wilhelmina married twice, firstly in October 1843 to Archibald Primrose, Lord Dalmeny (1809-1851), eldest son of Archibald Primrose, 4th Earl of Rosebery (1783-1868), whom she met three months before at a ball at Buckingham Palace.[3] They had two sons and two daughters before Dalmeny's early death to heart failure. Their eldest son, also named Archibald, inherited the earldom and went on to become prime minister.
She was married secondly in 1854 to Lord Harry Vane (1803–1891), youngest son of William Vane, 1st Duke of Cleveland (1766-1842); he succeeded his brother in the dukedom in 1864, and changed his surname to Powlett. They had no children, and on Cleveland's death all his titles became extinct, with the exception of the barony of Barnard.
Shortly before her 88th birthday, Lady Cleveland unexpectedly died of a cardiac arrest in Wiesbaden, Hesse, a week after undergoing successful eye surgery. "In spite of her advanced age the Duchess of Cleveland was an indefatigable traveller, and her faculties and interests remained undimmed," reported The Times in her obituary.[1]
Her historical works included: