For nearly 8,000 years, Atlantis has stood as the Lemurian outpost on the planet of Earth.
Per the Rule of Harinoth, Atlantis is an Category 4 outpost city, watching and guiding the indigenous sentient lifeforms until they were ready to be uplifted and joined with Lemurian society. Atlantis has provided some technical support and minor assistance, but is primarily content to serve as a guardian of the planet, and a shining example of what humanity can become.
When the Arturan/Lemurian War began nearly 500 years ago, things started to change. The Lemurian Union started to shift towards a more warlike stance. Research turned towards weapons, ship designs, and defensive systems. Atlantis, as it was not actively involved in the day-to-day running of Earth due to its outpost status, was partially converted into a research facility. This did not take away from its primary mandate of monitoring and protecting Earth, and resulted in a more expanded role for the Atlantean Science Directorate.