H.M.S. Melampus was one of the large group of "Leda" class 38-gun frigates ordered for the Royal Navy during the French Revolutionary and Napoleonic Wars, the last of which was not completed until the 1830's. Melampus herself, dating from about halfway through the building programme, was laid down in Pembroke dockyard in August 1817 and launched on 10th August 1820. Measured, like all her sisters, at 1,052 tons, she was also 150 feet in length with a 40 foot beam, and carried 28-18pdrs. as her main armament. Hulked in 1855 after thirty-five years service, she was initially put to work as a coastguard vessel at Southampton but was returned to Portsmouth for naval use in 1866. In 1886 she became a War Office ordnance storeship and after relinquishing that role in 1891, she was returned to the Admiralty in 1895 until eventually sold for breaking in 1906.