One of only two authentic old Jolly Rogers known in the world. The red background meant that she ship flying the flag would take no prisoners if their opponents put up a fight. The 18th century pirate flag is now on display at the National Museum of the Royal Navy.
This flag is from the 1780s, well after the period of Blackbeard and Captain Kidd and other golden age pirates. It is also very small, certainly not large enough to be seen from the deck of one ship to another at sea. Likely captured off North Africa. Traditionally Golden Age Pirates would have a pair of these, a flag with skulls, bones, and other death imagery to frighten upon us and signal that it was time to surrender, and a plain red or 'bloody" flag to signal that it was too late. In addition to these they usually carry various national flags as well to trick potential targets into thinking they were friendly. There were a few red jolly Rogers documented (not Henry Every's!), but none that I know of were used to signal no surrender and no prisoners, for which the pirates still typically used a plain bloody flag.
Skull carved in warthog ivory/ Crâne sculpté dans de l'ivoire de phacochère