Genii are under the leadership of Ladon Radim. Teyla led the Expedition to the Genii because her people had a trading arrangement with them. Secretly, though, these apparent farmers were actually soldiers who lived underground. They had advanced far enough in the sciences to create nuclear bombs, which they planned to use against the Wraith. Most of the Genii were wiped out by the Wraith, but the ones who survived organized under Radim or became mercenaries. The Genii were introduced in Stargate Atlantis: 1.08 "Underground".