The Defence-class ironclads were a class of two warships built for the Royal Navy between 1859 and 1862. The ships were designed as armoured frigates in response to an invasion scare sparked by the launch of the French ironclad Gloire and her three sisters in 1858. They were initially armed with a mix of rifled breech-loading and muzzle-loading smoothbore guns, but the Armstrong breech-loading guns proved unreliable and were withdrawn from service after a few years.