In a chapel in the old crenellated church of Mary of Zion in Aksum, Ethiopia is kept an object that emperors, patriarchs and priests have assured the world is the most important religious relic of all time: the tabota Seyon, Ark of the Covenant, the Ark of Zion. This Ark is alleged to be no other than the Ark that Moses had constructed at Sinai and which destroyed the walls of Jericho. It was brought into Jerusalem by King David and installed in a...