The Duke of Northumberland (1714-1786) married Elizabeth, Baroness Percy, only surviving child of 7th Duke of Somerset. He assumed the name and coat of arms of Percy, by Act of Parliament in 1750. He was Lord Lieutenant of Ireland 1763-5. He was created Duke of Northumberland Earl Percy (22 October 1766) and furthery created Lord Lovaine, Baron of Alnwick (28 January 1784).