HMS Endymion was a 40-gun fifth rate that served in the French Revolutionary Wars, the Napoleonic Wars, the War of 1812 and during the First Opium War. She was built to the lines of the French prize Pomone captured in 1794. Due to her exceptional handling and sailing properties, the Severn-class frigates were built to her lines, although the gunports were rearranged to mount an extra pair of guns per side, the ships were made of softwood and were not built until nearly the end of the Napoleonic Wars.