HMS Indefatigable was one of the 64-gun third-rate ships-of-the-line designed by Sir Thomas Slade in 1761 for the Royal Navy. She was built as a ship-of-the-line, but most of her active service took place after her conversion to a 44-gun razee frigate. She had a long career under several distinguished commanders, serving throughout the French Revolutionary Wars and the Napoleonic Wars. She took some 27 prizes, alone or in company, and the Admiralty authorised the issue of four clasps to the Naval General Service Medal in 1847 to any surviving members of her crews from the respective actions. She was broken up in 1816. Construction Indefatigable was ordered on 3 August 1780 (long after Slade's death), and her keel was laid down in May 1781 at the Bucklers Hard shipyard in Hampshire owned by Henry Adams. She was launched in early July 1784 and completed from 11 July to 13 September of that year at Portsmouth Dockyard as a 64-gun two-decked third rate for the Royal Navy. She had cost £25,210 4s 5d to build; her total initial cost including fitting out and coppering was £36,154 18s 7d. By that time, she was already anachronistic for the role of a ship of the line as the French only built the more powerful 74-gun ships, and was never commissioned in that role. Design modification In 1794, she was razéed; her upper gun deck was cut away to convert her into a large and heavily armed frigate. The original intention was to retain her twenty-six 24-pounder guns on her gundeck, and to mount eight 12-pounder guns on her quarterdeck and a further four on her forecastle, which would have rated her as a 38-gun vessel. However, it was at this time that the carronade was becoming more popular in the Navy, and her intended armament was altered on 5 December 1794 with the addition of four 42-pounder carronades to go on her quarterdeck and two on her forecastle. Indefatigable was thereafter rated as a 44-gun fifth-rate frigate, along with and , which were converted at about the same time. The work was carried out at Portsmouth from September 1794 to February 1795 at a cost of £8,764. On 17 February 1795, a further two 12-pounder guns were added to her quarterdeck, though her official rating remained unchanged. French Revolutionary Wars Captain Sir Edward Pellew Indefatigable was first commissioned in December 1794 under