Beneath the waters of Abukir Bay, at the edge of the Nile Delta, lie the submerged remains of the ancient Egyptian cities Canopus and Thonis-Heracleion, which sank more than a thousand years ago. They were dramatically rediscovered in the C20th and brought to the surface by marine archaeologists in the 1990s. The wealth of ancient artefacts from these excavations are now exhibited in the British Museum’s landmark exhibition. The curator tells the story of how two iconic ancient civilisations, Egypt and Greece, interacted in the late first millennium BC.