Flag flown by HMS Safari in WW II

The National Museum of the Royal Navy at the Portsmouth Historic Dockyard has a new exhibition — Jolly Roger: A Symbol of Terror and Pride. The website describes the exhibition as telling the story of the skull and crossbones flag, commonly known as the Jolly Roger, which has been associated with pirates for centuries. They also comment that “the history of its use by the Royal Navy who started flying the flag from First World War submarines is lesser known.”

Why did Royal Navy submarines fly pirate flags? Apparently, when the submarine was a very new and dangerous technology, many in the surface navy were not wildly enthusiastic about the new ships in the fleet.  In 1901, First Sea Lord Admiral Sir Arthur Wilson went so far as to say that submarines were “underhanded, unfair, and damned un-English” and that their crews should be hanged as pirates. The story goes that in response, in 1914 Lieutenant Commander Max Horton began flying the Jolly Roger after returning from successful patrols on the submarine HMS E9. The practice caught on, and soon other Royal Navy submarine commanders began flying pirate flags as well. Apparently, the Admiralty disapproved of the practice but was unable to stop it.

The practice became widespread during World War II, when flotilla commanders would issue pirate flags. The submarines then modified the skull and crossbones flags by adding bars or ship silhouettes to indicate enemy ships sunk or mines for minefields cleared. There were also symbols for clandestine operations and rescues at sea.

The flying of the Jolly Roger is not limited to the Royal Navy. The US super-secret spy submarine, USS Jimmy Carter, has been seen flying the skull and crossbones on returning to port. While some have speculated that the flag signifies another successful top-secret mission completed, the commander will not confirm or deny that that is the case, suggesting the flag is flown as a morale booster. 

The National Museum of the Royal Navy exhibition features an actual skull and crossbones flag captured from a pirate ship in the 1790s, as well as flags from submarines from the two world wars.

The oldest pirate flags were likely solid red, indicating “no quarter.” The name of the flag Jolly Roger is thought to have come from the French phrase “joli rouge” meaning “pretty red.”