...In 1940, the submarine HMS Osiris infiltrated the Adriatic Sea, a body of water that then-Italian Prime Minister Benito Mussolini said could not be penetrated. Once inside, the Osiris sank the Italian destroyer Palestro. Upon its return to one of the British flotillas in the Mediterranean, the flotilla’s commander signaled to the Osiris that the submarine would fly a special recognition following its successful mission and that the Osiris was “not to come alongside until the identity signal is showing,” Compton-Hall wrote. A launch from the flotilla then delivered a package marked “JR” to the Osiris. Inside, was the iconic black and white pirate flag, which the Osiris then proudly ran up its tower before reuniting with the flotilla. From then on, flotilla commanders awarded the Jolly Roger to submarines after their first successes.
cool.