There’s a warship that served six different nations.
Far more so than the British, the French Emperor Napoleon III desired a Confederate victory in the American Civil War. So in 1863, the Confederate government was able to commission the firm of Lucien Arman in Bordeaux to build the 1,390 ton ironclad ram ostensibly named the Sphinx. It was a well-built and truly modern warship that could have seriously threatened the commerce of the United States.
What makes this ship remarkable is that during its 24-year career, it served 6 different nations: France, Denmark, the Confederate States of America, Spain, the United States of America, and Japan.