After sacking its capital at Delhi, he plundered the treasuries of the Mughal emperors, and hauled the wealth westward, over the Hindu Kush, towards his kingdom of Persia.
With the knowledge that his health was deteriorating, Ahmad Shah is alleged to have concealed the bulk of the treasure before his death.
A century ago, Amir Abdur-Rahman sent convicts to hunt in the dangerous tunnels commonly found in the region.
His father, Idries Shah, was Afghanistan's most famous writer of modern times, and was also preoccupied with the alleged lost treasure.
His own fascination for riddle led him to write a bestselling novel about the alleged treasure of Ahmad Shah, Kara Kush.