The books Theogony by Hesiod, the Iliad and Odyssey by Homer, and Plato’s Atlantis were all written during the Classical Age after the Dark Age in Greece, preceded by the so-called bronze age collapse (which was the end of the Ice Age), the “gods” in the classical works by Homer and Hesiod circa 700 b. c. which overlapped demi-gods in Plato’s Atlantis, those “gods” Hades of the underworld who was Gades (brother of Atlas) in Plato’s tale, and Posidon of the sea the same in all three works. Posidon was Sidon, a son of Canaan (see Genesis 10), so when the Ice Age had ended circa 1400 b. c., the demise of Atlantis was begun memorialized by (canaanite) Posidon having lost to Athena in vying for Athens, and Hades his son relegated to the underworld.
