Davidson, Thomas, 1722-1781.

Hugh Smithson, fourth baronet of Stanwick in Yorkshire, married the heiress to the Percy title and estates in 1740 over the objections of her family. In 1750, shortly after her succession as Baroness Percy suo jure, Hugh Smithson took the surname Percy by Act of Parliament and was seated in the House of Lords as Earl of Northumberland. He was created Duke in 1766 with the support of William Pitt.

Northumberland was active in politics for over thirty years. He instituted many agricultural improvements on the Percy estates, reclaiming land and rebuilding laborers' cottages, and developed highly profitable coal mines. He renovated Alnwick Castle, hiring Robert Adam as architect and designer, was elected a Fellow of the Royal Society, and was a founding Trustee of the British Museum.

The couple had two sons and one daughter, Lady Elizabeth, who died unmarried. In addition, Northumberland had several natural children. His son James Smithson, born in France to Elizabeth Keate Macie in 1765, was trained as a scientist at Oxford and died in Genoa in 1829, leaving the estate that eventually became the founding bequest of the Smithsonian Institution.

Lady Elizabeth Percy, Duchess of Northumberland, died in 1776. Hugh Percy, Duke of Northumberland, died on June 6, 1786.

Eldest son of the first Duke, Hugh Smithson assumed the surname of Percy by Act of Parliament along with his father in 1750. He entered the Army in 1759 and in 1764 married Lady Anne Stuart, daughter of Lord Bute. He served with distinction at the Battle of Lexington and was named Lieutenant-General of the Army in America early in 1777, but was recalled from command after many disputes with General Howe. He continued his military career, however, taking command of the Percy yeomanry regiment in 1798 and a colonelcy in the horse-guards in 1806.

Northumberland was granted a divorce in Parliament from Lady Anne in 1779 on the grounds of her adultery; he immediately married Frances Julia Burrell, with whom he had three daughters and two sons. He continued his father's agricultural improvements, and when corn prices fell after 1815, he reduced his rents by twenty-five percent; his tenants built a monument to him in gratitude. He held twice-weekly gatherings at Alnwick Castle, inviting tenants and local tradespeople. The second Duke of Northumberland died suddenly "of rheumatic gout" in July 1817. His widow died in May, 1820.

Hugh Percy, eldest son of the second Duke, was educated at St. John's College, Cambridge and elected M.P. for Buckingham and for Westminster in 1806. While in Parliament he proposed a bill to abolish slavery in the British colonies, but it failed. In 1807 he took his seat in the House of Lords as Baron Percy. Ten years later he succeeded his father as Duke of Northumberland. He married Lady Charlotte Florentia Clive, who was for some years Governess to the future Queen Victoria. The couple had no children.

Northumberland was Ambassador Extraordinary to France at the coronation of Charles X in 1825. In January 1829 he was appointed Governor-General of Ireland, shortly before the passage of the Catholic Relief Bill, and was recalled when the ministry of the Duke of Wellington fell in November 1830. He was elected Chancellor of Cambridge in 1840, a post he held until his death at Alnwick Castle on February 12, 1847.

From the guide to the Percy family papers, 1760-1822, (Beinecke Rare Book and Manuscript Library)