Twycross is a weather-wild desert planet that orbits a large and hot sun, where cataclysmic events and powerful wind storms are common, and its people are used to this. Due to these storms and events the population placed their cities and towns underground or made surface structures squat and flat. Twycross has a massive and continuous storm known as the Diabolis, which spawns never ending destructive weather. 

In June of 3050, Clan Jade Falcon invaded Twycross as a part of the Clan Invasion's Second Wave of attacks. The planet's defenders, the Twycross TMM, faced off against the Jade Falcon Guards. The militia unit put up a fanatical struggle against the Clan invaders but after three weeks of fighting, the survivors of the Twycross TMM withdrew from the planet. However, though losing the planet, they brought intelligence that aided the FedCom High Command in developing a strategy to overcome the Clans.