Humans from Africa are migrating across the ice bridge to Atlantis, which is in the Atlantic Ocean
Humans originally settled in Atlantis around 10,000 BCE. Hunter Gatherers go from Europe to Atlantis during the Ice Age. A temporary ice/land bridge was there for them to cross over. By 9,000 BCE it was gone. The ice was incredibly strong, but yielded no usefulness except ice for water. Once in Atlantis, humans start to farm. The reason for this was because with no food source they knew, humans looked for alternate methods of food. Plants and grains had been used for a while, but in Atlantis, the knowledge of planting seeds was first put to use. This developed their society faster than humans who hadn't crossed to Atlantis yet.
Take over of Atlantis by the Atlains. Atlains (Red) Latens (Green)
By 7,000 BCE, civilization in Atlantis had begun. There were several tribes, factions, and even kingdoms that were fighting over territory. The most important of these were the Latens and Atlains. These two kingdoms fought for power over hundreds of years, and by 6,800 BCE, The Four Day War began. The Latens had lost and surrendered in only four days to the Atlains. This was because of how much strength the Atlain military had. Their superior army had overtaken the well defended walls of the kingdom's capital. Once the walls were down, it was a massacre against the Latens. Only children inside the walls were spared. As a whole, Atlantis was under Atlain rule. A year later, the Atlains named their country Atlantis, after the continent.
In the year 6,800 BCE, the Atlains reorganized into the First Atlantian Empire.