Captain Kidd’s treasure, Gardiners Island

The island cache was real, and it was recovered in 1699

William Kidd, born in Dundee and settled in New York, was a successful privateer when in 1695 the Earl of Bellomont, governor of New York, Massachusetts Bay and New Hampshire, gave him a royal commission to hunt pirates and French ships in the Indian Ocean. He sailed in the Adventure Galley the next year, found few targets, lost much of his crew and faced mutiny. In 1698 he took his greatest prize, the 400-ton Quedagh Merchant, hired by Armenian merchants but captained by an Englishman, with much of her cargo thought to belong to the East India Company. By then opinion in England had turned, and he was denounced as a pirate.

Sailing home, he left his marked ship in the Caribbean, sold off goods through the fence William Burke, and came north in a sloop. Before facing the authorities he buried a small cache of treasure on Gardiners Island, off the eastern tip of Long Island, at a spot known as Cherry Tree Field, hoping to use its location as a bargaining tool. It did not work. Bellomont, afraid of being implicated himself, lured Kidd into Boston with false promises of clemency and had him arrested on 6 July 1699, and reportedly had the Gardiners Island cache dug up and sent to England as evidence. Tried in London for murder and five counts of piracy, Kidd was hanged at Execution Dock in Wapping on 23 May 1701. The first rope broke, and so, by the BBC's account, did the second; the third held.

The belief that he left far more buried made him a legend. Treasure hunters have dug for it on Oak Island in Nova Scotia, across Suffolk County on Long Island, on Charles Island in Milford, the Thimble Islands and Cockenoe Island in Connecticut, and along the Rahway River in New Jersey. On Block Island it was said he filled Mercy Raymond's apron with gold and jewels for her provisions. Washington Irving's The Devil and Tom Walker turns on his hidden gold, and the legend helped inspire Robert Louis Stevenson's Treasure Island.

The search still makes headlines. In May 2015 a team led by the marine archaeologist Barry Clifford brought up a bar of about 50 kg from a wreck off Île Sainte-Marie in Madagascar, thought to be the Adventure Galley, and announced Kidd's silver. In July 2015 a UNESCO advisory body reported that it was 95 percent lead, and suggested the wreck was part of the old port works.