The Clarke Quadrant lies in the Gemini Sector and consists of the Blockade Point Alpha, Blockade Point Charlie, Blockade Point Tango, CMF-A, Hyades, Lisacc, Mah'Rahn, Midgard, Nitir, Perry, Ragnarok, Rikel, Sumn-Kp'ta, Surtur, Tingerhoff and Tr'Pakh systems.
Clarke was the heart of the Terran Confederation's military entrenchment begun in 2639, which ultimately led to the initial settlement of the entire Sector. The seat of all Gemini’s naval forces, Perry Naval Base, was located in Clarke Quadrant (specifically in the Perry system). Due to the strength of Confederation Naval forces in the region during the Terran-Kilrathi War, there were no full scale battles in Gemini from 2658 through the start of the Nephilim War. Several major battles during the Nephilim War led to the de-population of much of the Quadrant, particularly after the complete destruction of Perry Naval Base.