Keira Knightley makes a sexy on-screen buccaneer in Pirates of the Caribbean: Dead Man's Chest, but were there really famous female pirates?

There were. Anne Bonny and Mary Read were just as cunning as their male pirating counterparts and perhaps more ruthless. When the males aboard their ship cowered below deck in the face of capture, the two women shouted at them to come up and fight - and if they didn't, Bonny and Read shot them. How they ended up working together aboard the same ship, and later, facing the same hangman, is pure coincidence.

Both Bonny and Read were illegitimate children. Bonny's father, William Cormac, was a lawyer in Ireland who had an affair with a servant. When his wife found out their maid was pregnant, she sought to destroy him and succeeded in ruining his practice. He moved to North America with his daughter, where he acquired a large plantation in Carolina. It caught the eye of one of Anne's suitors, James Bonny, who married her but failed to acquire the property - Cormac had disowned his daughter after her nuptials. In 1718, the couple moved to the Bahamas and James became a spy for bounty hunters. His wife despised him for taking such a job and began hanging out with the very pirates he sought. She and 'Calico Jack' Rackham embarked on an affair and she boarded his ship for a life of piracy.

Read grew up in London. Her mother had had a son, but both the father and child had died before Read's mother gave birth to a girl. In a bid to obtain support from her late husband's family, she pretended her daughter, Mary, was the son who had died. Read passed herself off as a boy throughout her childhood and, as an adult 'man', she went to Flanders to join the infantry. She fell in love with a Flemish soldier, confessed her true identity and the pair were married. They opened a tavern but her husband died soon afterwards. Read - assuming her male persona again - headed to the West Indies. Her ship was attacked by Rackham and his English pirates, and Read, being the only English person on board the target ship, was invited to join the pirates.

Also disguised as a man, Bonny was already a pirate on Rackham's ship at this stage, and when the pair discovered each other's gender secret, they became good friends. Rackham, unaware that Read was a woman, grew jealous of Bonny's affection for her and would have killed his perceived rival if the women had not revealed Read's identity. He agreed to keep their secret from the rest of the crew. The two women gained reputations for their ferocity, fighting spirit and skill with pistols. In 1720, their pirate ship, Revenge, was captured near Jamaica and everyone on board was sentenced to hang. By claiming they were pregnant, Bonny and Read escaped the noose. Read later died in prison while it is suspected Bonny was freed after her father pulled strings on her behalf.