George Fitzroy (1665-1716), third son of Barbara, duchess of Cleveland, the wife of Roger Palmer, earl of Castlemaine, by King Charles II., was created by his father earl of Northumber land in 1674, and duke in 1683. This second dukedom of North umberland became extinct on his death at Epsom on July 3, 1716. Meanwhile Elizabeth Percy, daughter of Joceline, the nth earl, had married Charles Seymour, 6th duke of Somerset; and her son Algernon, the 7th duke, was in 1749 created Baron Warkworth and earl of Northumberland, with remainder to his son-in-law, Sir Hugh Smithson, Bart., son of Langdale Smith son of Langdale, Yorkshire. Sir Hugh Smithson (c. 1714-1786) took the name and arms of Percy on inheriting the earldom in 175o; in 1766 he was created Earl Percy and duke of Nor thumberland; and in 1784 he was further created Baron Lovaine of Alnwick, with special remainder to his second son, Lord Al gernon Percy. He took a prominent part in politics as a follower of Lord Bute, and was one of George M.'s confidential advisers, holding the office of lord-lieutenant of Ireland from 1763 to 1765, and that of master of the horse from 1778 to 1780. He was a man of cultivated tastes, and spent much money in repairing and improving Alnwick castle and his other residences. His wife, Elizabeth (1716-1776), inherited in her own right her father's barony of Percy. The duke was succeeded by his eldest son
Hugh ; and his second son Algernon, Lord Lovaine, was created earl of Beverley in 1790.
Hugh, 2nd duke of this line (1742-1817), first inherited his mother's barony of Percy. He was present at the battle of Min den, and although in parliament, where he was member for Westminster from 1763 to 1776, he had opposed the policy that led to the American war, he proceeded to Boston in 1774 as colonel commanding the 5th Fusiliers, a regiment that has since then been known as the Northumberland Fusiliers. He succeeded to the dukedom in 1786, and became general in 1793. His son Hugh, 3rd duke (1785-1847), was lord-lieutenant of Ireland in 1829-1830, when the Catholic Emancipation Act was passed, and was pronounced by Sir Robert Peel "the best chief governor that ever presided over the affairs of Ireland." Both he and his brother Algernon, 4th duke (1792-1865), who was created Baron Prudhoe in 1816, died without issue ; the barony of Percy de volved on their great-nephew, the duke of Atholl, and the duke dom passed to George (1778-1867), eldest son of Algernon, 1st earl of Beverley, and so to his son, the 6th duke (1810-1899), and grandson, the 7th duke (1846-1918).
See Edward Barrington de Fonblanque, The House of Percy (2 vols., 1887) ; G. E. C(okayne), Complete Peerage, vol. vi. (1895).