Admiral Sir Astley Cooper Key, GCB, FRS, ADC (18 January 1821 – 3 March 1888) was a Royal Navy officer. As a junior officer he saw action at the Battle of Vuelta de Obligado in November 1845 during the Anglo-French blockade of the Río de la Plata and took part at the Battle of Bomarsund in August 1854 and the Bombardment of Sveaborg in August 1855 during the Crimean War. He also went ashore with the naval brigade to take part in the Battle of Canton in December 1857 during the Second Opium War. He later commanded a specially-formed Baltic Fleet created in February 1878 to intimidate Russia from entering Constantinople during the closing stages of the Russo-Turkish War. He became First Naval Lord in August 1879 in which role he was primarily interested in administration and technology rathe