John Rackham (26 December 1682 – 18 November 1720), commonly known as Calico Jack, was an English pirate captain operating in the Bahamas and in Cuba during the early 18th century (Rackham is often spelled as Rackam or Rackum in historical documentation, and he is also often referred to as Jack Rackham). His nickname derived from the calico clothing he wore, while Jack is a diminutive of "John."
Active towards the end (1718–20) of the "golden age of piracy" (1650–1730) Rackham is most remembered for two things: the design of his Jolly Roger flag, a skull with crossed swords, which contributed to the popularization of the design; and for having two female crew members, Mary Read and Rackham's lover Anne Bonny.
After deposing Charles Vane from his captaincy, Rackham cruised the Leeward Islands, Jamaica Channel, and Windward Passage. He accepted a pardon some time in 1719 and moved to New Providence, where he met Anne Bonny, who at the time was married to James Bonny. When Rackham returned to piracy in 1720 by stealing a British sloop, Bonny joined him. Their new crew included Mary Read. After a short run he was captured by pirate hunter Jonathan Barnet in 1720, before being hanged in November of the same year in Port Royal, Jamaica. 

The first recorded uses of the skull-and-crossbones symbol on naval flags date to the 17th century. It possibly originated among the Barbary pirates of the period, which would connect the black colour of the Jolly Roger to the Muslim Black Standard (black flag). But an early reference to Muslim corsairs flying a skull symbol, in the context of a 1625 slave raid on Cornwall, explicitly refers to the symbols being shown on a green flag. There are mentions of Francis Drake's flying a black flag as early as 1585, but the historicity of this tradition has been called into question. Contemporary accounts show Peter Easton using a plain black flag in 1612; a plain black flag was also used by Captain Martel's pirates in 1716, Blackbeard, Charles Vane, and Richard Worley in 1718, and Howell Davis in 1719. An early record of the skull-and-crossbones design being used on a (red) flag by pirates is found in a December 6, 1687 entry in a log book held by the Bibliothèque nationale de France. The entry describes pirates using the flag, not on a ship but on land. 17th and 18th century colonial governors usually required privateers to fly a specific version of the British flag, the 1606 Union Jack with a white crest in the middle, also distinguishing them from naval vessels. Before this time, British privateers such as Sir Henry Morgan sailed under English colours.[5] An early use of a black flag with skull, crossbones, and hourglass is attributed to pirate captain Emanuel Wynn in 1700, according to a wide variety of secondary sources.[14] Reportedly, these secondary sources are based on the account of Captain John Cranby of HMS Poole and are verified at the London Public Record Office. With the end of the War of the Spanish Succession in 1714, many privateers turned to piracy. They still used red and black flags, but now they decorated them with their own designs. Edward England, for example, flew three different flags: from his mainmast the black flag depicted above; from his foremast a red version of the same; and from his ensign staff the English national flag. Just as variations on the Jolly Roger design existed, red flags sometimes incorporated yellow stripes or images symbolic of death. Coloured pennants and ribbons could also be used alongside flags. Marcus Rediker (1987) claims that most pirates active between 1716 and 1726 were part of one of two large interconnected groups sharing many similarities in organisation. He states that this accounts for the "comparatively rapid adoption of the piratical black flag among a group of men operating across thousands of miles of ocean", suggesting that the skull-and-crossbone design became standardized at about the same time as the term Jolly Roger was adopted as its name. By 1730, the diversity of symbols in prior use had been mostly replaced by the standard design.