The Headquarters Allied Command Europe Rapid Reaction Corps, (HQ ARRC or ARRC) was created in 1992 in Bielefeld based on the former British I Corps (or I (BR) Corps ). It was originally created as the rapid reaction corps sized land force of the Reaction Forces Concept that emerged after the end of the Cold War, with a mission to redeploy and reinforce within Allied Command Europe (ACE) and to conduct Petersberg missions out of NATO territory.
Since 2002 however the HQ has been re-roled (with five other corps HQs of other NATO nations) as a High Readiness Force (Land) HQ (HRF(L)) with a broader mission. The formation HQ is under Operational Command of Supreme Allied Commander, Europe (SACEUR). The ARRC has a notional Force Pool of Combat, Combat Support and Combat Service Support units with which to train and execute its mission. However in reality COMARRC commands no forces until he receives an Activiation Order from SACEUR. On receipt of ACTORD, forces from troop contributing nations, generated through the NATO Force Generation process are passed into his Operational Command for the duration of the operational deployment.
Although the corps is commanded by a British Army lieutenant-general, the corps is no longer a purely British formation HQ. The UK is the \'framework nation\' and provides about 80% of the funding and 60% of the staff for the HQ, which since 1994 has been based in the Rheindahlen Military Complex, Germany. A purely national corps headquarters could be quickly reconstituted if necessary.
ARRC took command of the International Security Assistance Force in Afghanistan on 4th May 2006. Previously, it was deployed as the headquarters commanding Land Forces during the Kosovo War in 1999 and, prior to that, commanded the Land Forces of NATO\'s first ever deployment as part of the IFOR operation in Bosnia in 1995/6. In mid-2004, rumours surfaced that contingency plans were being prepared for the ARRC to deploy to Iraq to command the foreign forces in the south of the country.
ARRC will be relocating to the former RAF Innsworth site outside Gloucester in England, in 2009.
