In 2167 the Colonial Defence Authority was created. Initially it operated out of HMS Thule, a Titan-class command & control vessel. In 2170 the Royal Navy saw it fit to designate a permanent base to the Colonial Defence Authority. There were three bases initially created, CDA Aberdeen, CDA Tyrone and CDA Cheltenham.
In 2183 in the face of funding cuts, the Royal Navy announced the closure of CDA Aberdeen and CDA Tyrone. CDA Tyrone was the largest of the three bases, and had 4 frigates permanently on station as well as a force of 5,000 soldiers, 2 Colonial Defence Regiment. All 4 frigates were decommissioned with the closure of the Tyrone Facility and the 2 Colonial Defence Regiment was disbanded.