Algernon Percy, 4th duke of Northumberland and 1st Baron Prudhoe (1792–1865)

Joined the British navy, 1805; first lord of the Admiralty, 1852–3; admiral, 1862. Created Baron Prudhoe, 1816; knighted, 1853; succeeded to the dukedom in 1847. Fellow of the Astronomical and Geological Societies; president of the Royal Institution; trustee of the British Museum. Developed the gardens at Syon House, Isleworth, Middlesex. FRS 1818.