Explorers unlock the mystery of ‘pirate king’ Henry Avery who vanished after huge heist at sea

18th-century engraving of the legendary English ‘pirate king’, Henry Avery, ‘taking one of the Great Mogul’s ships’. His fate remains a mystery. Photograph: Pictorial Press Ltd/Alamy

In 1695, Henry Avery led his 160-strong crew to pull off the most lucrative heist in pirate history on the high seas, amassing gold, silver, sapphires, emeralds and diamonds worth more than £85m in today’s money. He became the most wanted criminal of his day but vanished without trace and was the stuff of legend for 300 years.

Now shipwreck explorers Dr Sean Kingsley and Rex Cowan claim to have solved what they call the longest cold case in pirate history: the “pirate king” had entered the service of the king of England, William III, as a spy.