"If you go to St Mark's cathedral in Venice, there's a medieval depiction showing people using the three great pyramids of Giza as granaries in Joseph's story," says John Darnell, a professor of Egyptology at Yale University. The belief was also popularised by Saint Gregory of Tours, a sixth century Frankish bishop, who wrote: "They are wide at the base and narrow at the top in order that the wheat might be cast into them through a tiny opening, and these granaries are to be seen to the present day." The Book of John Mandeville, a popular 14th Century travel...