Catherine Sheffield, Duchess Of Buckingham And Normanby

Catherine Sheffield, Duchess of Buckingham and Normanby, (née Lady Catherine Darnley), was born circa 1681 and died on 13 March 1743. She was an illegitimate daughter of King James II of England and Catherine Sedley, Countess of Dorchester. Her paternity was subject to some doubt due to the existence of other lovers attributed to Catherine Sedley. She was granted the surname Darnley, referencing her paternal ancestor Lord Darnley. By royal warrant, Lady Catherine Darnley was accorded the status of a duke’s daughter in the order of precedence. Her arms, granted by King James II, are incorporated into the heraldic arms of the Marquess of Normanby, signifying royal recognition of her as his natural child.

Her first marriage was to James Annesley, 3rd Earl of Anglesey. The marriage took place on 28 October 1699 at Westminster Abbey. The marriage was dissolved in 1701 by an Act of Parliament on grounds of her husband's cruelty. Lady Catherine claimed that her husband had attempted to murder her. She left him while he was defending himself from her accusations in the House of Lords. James Annesley contracted tuberculosis and died in early 1702. They had one daughter, Lady Catherine Annesley, born around 1700, who married William Phipps and later John Sheldon (or Skelton). Lady Catherine Annesley's lifespan is approximately 1700 to 1736.

On 16 March 1706, Lady Catherine married John Sheffield, 1st Duke of Buckingham and Normanby, at St Martin-in-the-Fields. The duke, a supporter of King James II, was over thirty years her senior. They had three children, two of whom died in infancy: John Sheffield, Marquess of Normanby (born 1710), Robert Sheffield, Marquess of Normanby (born 1711, died in 1715), and Edmund Sheffield, 2nd Duke of Buckingham and Normanby (born 1716, died 1735). The duke's previous marriages were reputed to be unhappy, but he reportedly cared deeply for Lady Catherine. Alexander Pope noted the duke's affection, stating that he would abandon his work and leave his books to be near her during any disagreement. Upon the duke’s death in 1721, she engaged Alexander Pope and Francis Atterbury to produce a memorial edition of his works.

All of Lady Catherine’s children predeceased her, leading to the extinction of the dukedom. Her husband's estates passed to his illegitimate son, Sir Charles Herbert Sheffield, 1st Baronet. Her descendants through her daughter Lady Catherine Annesley included notable figures such as Constantine Phipps, 1st Baron Mulgrave; Henry Phipps, 1st Earl of Mulgrave; the Hon. Charles Phipps, MP; and the Hon. Edmund Phipps.