Atlantis is a fictional island mentioned within an allegory on the hubris of nations in Plato's works Timaeus and Critias,[1] where it represents the antagonist naval power that besieges "Ancient Athens", the pseudo-historic embodiment of Plato's ideal state in The Republic. In the story, Athens repels the Atlantean attack unlike any other nation of the known world,[2] supposedly giving testament to the superiority of Plato's concept of a state.[3][4] The story concludes with Atlantis falling out of favor with the deities and submerging into the Atlantic Ocean.

Despite its minor importance in Plato's work, the Atlantis story has had a considerable impact on literature. The allegorical aspect of Atlantis was taken up in utopian works of several Renaissance writers, such as Francis Bacon's New Atlantis and Thomas More's Utopia.[5][6] On the other hand, nineteenth-century amateur scholars misinterpreted Plato's narrative as historical tradition, most famously in Ignatius L. Donnelly's Atlantis: The Antediluvian World. Plato's vague indications of the time of the events—more than 9,000 years before his time[7]—and the alleged location of Atlantis—"beyond the Pillars of Hercules"—has led to much pseudoscientific speculation.[8] As a consequence, Atlantis has become a byword for any and all supposed advanced prehistoric lost civilizations and continues to inspire contemporary fiction, from comic books to films.

While present-day philologists and classicists agree on the story's fictional character,[9][10] there is still debate on what served as its inspiration. As for instance with the story of Gyges,[11] Plato is known to have freely borrowed some of his allegories and metaphors from older traditions. This led a number of scholars to investigate possible inspiration of Atlantis from Egyptian records of the Thera eruption,[12][13] the Sea Peoples invasion,[14] or the Trojan War.[15] Others have rejected this chain of tradition as implausible and insist that Plato created an entirely fictional nation as his example,[16][17][18] drawing loose inspiration from contemporary events such as the failed Athenian invasion of Sicily in 415–413 BC or the destruction of Helike in 373 BC.[19]