Pirates, Skulls and Crossbones
The Jolly Roger is any of various flags flown to identify a ship's crew as pirates. The flag most usually identified as the Jolly Roger today is the skull and crossbones, a flag consisting of a human skull above two long bones set in an x-mark arrangement on a black field. This design was used by several pirates, including Captains Edward England and John Taylor. Some Jolly Roger flags also include an hourglass, another common symbol representing death in 17th- and 18th-century Europe. Despite its prominence in popular culture, plain black flags were often employed by most pirates in the 17th-18th century. Historically, the flag was flown to frighten pirates' victims into surrendering without a fight, since it conveyed the message that the attackers were outlaws who would not consider themselves bound by the usual rules of engagement—and might, therefore, slaughter those they defeated (since captured pirates were usually hanged, they did not have much to gain by asking quarter if defeated). The same message was sometimes conveyed by a red flag.
It is thought that the French "jolie rouge" (red flag) is the origination of the Jolly Roger or the Skull and Crossbone. This flag originated with the Knights Templars. After they were disolved many could not make a living except as brigands and sea pirates. Other members were skilled as masons and craftsmen. Those who had no other skills other than what they were trained for (soldiers of God), took to the seas.
The flag known as the Skull and Cross-Bones was the choice of pirates long after the Crusades. The religious significance of the elite Order of the Knights Templar was turned into pirates who many feared. The skull and cross-bones signified death much like the skull and crossbones on a bottle of poison. It meant surrender to our ship or die.
The skull and two bones meant resurrection to the Knights Templar. The skull and cross-bones, alluded to Gol'gotha - "the place of the skull" - and the cross - where Jesus Christ died.