The Headquarters Allied Command Europe Rapid Reaction Corps, (HQ ARRC or ARRC) was created in 1992 based on the former British I Corps. The unit is commanded directly by NATO's SACEUR (Supreme Allied Commander, Europe), and as implied by its title, is able to deploy anywhere within Allied Command Europe (ACE) at short notice.
Although the corps is commanded by a BritishLieutenant General, the corps is no longer a purely British formation, although the UK is the 'framework nation' and provides most of the staff for the headquarters in Rheindahlen, Germany. A purely national corps headquarters could be quickly reconstituted if necessary.
ARRC was last deployed as the headquarters commanding land forces during the Kosovo War in 1999 and also saw service in Bosnia, commanding the initial stages of the IFOR deployment prior to that in 1996. 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. It is planned to deploy the corps to Afghanistan in 2006 in order for it to command the International Security Assistance Force
The ARRC is the land component of the ACE RapidReaction Forces.
The Headquarters of the ARRC is under the command and control of the Supreme Allied Commander Europe (SACEUR) in peacetime, with the Headquarters of MND(C) under operational command of Commander, ARRC.
The Headquarters of the ARRC assumed, for the first time, command of the land component of the NATO-led Peace Implementation Forces (IFOR) in Bosnia and Herzegovina on 20 December 1995.
The present active corps in the US Army are I Corps ("eye core"), III Corps, V Corps, and XVIII Airborne Corps; their numbers derive from four of the 30-odd corps that were formed during WWII.
In the British Army, a corps tends to be a grouping by common function (eg, the Infantry corps, the Royal Logistics Corps, Royal Corps of Signals).
I Corps of the British Army of the Rhine was redesignated the AlliedRapidReactionCorps in 1994.