HMS Edinburgh was a 74-gun third rate ship of the line of the Royal Navy, launched on 26 November 1811 at Rotherhithe. Between 1837 and 1841 she served in the Mediterranean, including operations off the coast of Syria and Lebanon in the Syrian War. In 1846 she was taken in hand at Portsmouth Dockyard and converted to steam-powered screw propulsion as a 'blockship'. The conversion was completed on 19 August 1852. In this transformation her displacement was increased to 2,598 tons and her complement of guns reduced to 60 (or 56: reports differ). She acted as guard ship for Devonport until February 1854, when she was assigned to the fleet sent to the Baltic under Sir Charles Napier. She was the flagship of Rear-Admiral Henry Ducie Chads, third in command of the fleet, and took part in the bom