HMS Leopard was a 50-gun 4th rate ship of the line of the Royal Navy.
Her keel was laid down in 1775 at Portsmouth Dockyard and she was finally launched in 1790 from Sheerness. In early 1807, a number of British and American sailors deserted their respective ships, then blockading French ships in Chesapeake Bay, and joined the crew of the USS Chesapeake. Jack Aubrey was her captain when he had to transport convicts to Australia, when diseases killed over half the men, and forced to Captain to sail towards South America. Later they stop near Brazil and flee from a Dutch 74 called Waakzaamhied hunting in the area. The Chase brings the two ships down to Cape Horn. In the chase the Leopards stern chasers took off the Waakzaamhied's foremast which caused her to sink in the raging seas. The Leopard begins to leak and over half the crew led by Grant leave in the boats. They stop at Desolation Island and encounter an American whaler headed home. After repairs Jack is able to get her back to a frendly port and the Leopard is made into a transport ship. She transports Stephen Maturin to the fictional Sweedish island of Grimsholm.