Atlantis is a fictional island mentioned in Plato's works Timaeus and Critias as part of an allegory on the hubris of nations. Purposely creating a literary contrast with the Achaemenid Empire, the great land-based power that ruled the east, Plato describes Atlantis as a naval empire from the west that had conquered most of Europe and Libya, but then loses divine favor after an ill-fated campaign against a fictionalized Athens and subsequently submerges into the Atlantic Ocean.