A research and exploration institute. The organization originated as a local defence force operating at Sol-Jupiter L5 during the Sundering, but it reinvented itself and became prominent during the First Federation, and remained active into the Integration period. The Lagrange Defenders were especially influential in early colonial efforts in the Inner Sphere (New Mars is just one example) and in the field of xenopaleontology. They are especially well known for having discovered the first evidence of interplanetary-level xenosophont technology in 1460, and are most famous of all for their discovery of the Tunh wormhole. Though the organization no longer exists under that name in the Inner Sphere or Middle Regions, there are persons and groups claiming to represent it still active in the Outer Volumes.