Admiral Sir William Sydney Smith, always known as Sydney (1764-1840) served unofficially for the Swedes in Russia and was made Knight Grand Cross of the Order of the Sword by Gustavus III in 1790. He was captured fighting against the French in 1796 and was held as a privateer until he escaped, or was allowed to escape, two years later. His independent behaviour annoyed Nelson when Smith was serving in the Eastern Mediterranean, where he relieved Acre in 1799; he also quarrelled with Sir John Moore of Corunna. He was M.P. for Rochester from 1802. He fomented rebellion in Southern Italy in 1806. A rear-admiral in 1805 and vice-admiral in 1810, he retired in June 1815, with the rank of admiral, to Paris, where he died.
For the possible provenance up to 1911 see the entry for Admiral Parker, lot 50.