Ireland was
partitioned in mid-1921. On 7 December 1922, the day after the establishment of the
Irish Free State, the Parliament of Northern Ireland resolved to address
King George V to opt out of the Irish Free State. The same year (1922), the first General Officer Commanding, Northern Ireland District was appointed, Major General Sir
Archibald Cameron. His headquarters was established at
Victoria Barracks, Belfast; he served until 1925. During the
Second World War the role of the District was enhanced from internal security to that of combatting any threat of invasion from the
Republic of Ireland. With the emergence of
the Troubles, which started in Northern Ireland in the late 1960s, the role of HQ Northern Ireland increased substantially as it took responsibility for "assisting in the defeat of
terrorism and the maintenance of
public order" and by 1972 it had 27,000 troops under its command. On 31 July 1972,
Operation Motorman was launched, the biggest British military operation since the
Suez Crisis of 1956 and the biggest in Ireland since the
Irish War of Independence. It aimed to eradicate the 'no-go zones' that had built up in several areas across Northern Ireland. In the days before 31 July, about 4,000 extra troops were brought into Northern Ireland. Several Centurion
AVRE demolition vehicles, derived from the
Centurion tank and fitted with bulldozer blades, were used. They were the only heavy armoured vehicles to be deployed operationally by the British Army in Northern Ireland during the Troubles. The tanks had been transported to Northern Ireland on board the amphibious landing ship
HMS Fearless, and were operated with their turrets traversed to the rear and main guns covered by tarpaulins. On 30 January 2006 the
Secretary of State for Defence announced to the House of Commons that
19 Light Brigade, then stationed at
Catterick, would be re-roling into a light brigade and relocating to
Scotland and
Northern Ireland. On 10 May 2006 it was further announced that "in addition to the HQ and other units of 19 Light Brigade that we expect to relocate to Northern Ireland in 2007 and 2008, a new and non-deployable regional brigade headquarters will form at
Thiepval Barracks,
Lisburn. The current
107 (Ulster) Brigade, based at
Ballymena, will merge on 15 December this year into
HQ 39 Infantry Brigade, which will itself be replaced by the new regional brigade headquarters,
38th (Irish) Brigade under the command of the
2nd Division, on 1 August 2007". with residual regional functions being migrated to HQ 2 Division in Edinburgh. Other services had a smaller 'footprint' in the province during the Troubles. The RAF's presence in Northern Ireland was based at
RAF Aldergrove, and
230 Squadron was based there for many years, among other units. The Royal Navy no longer maintain a regular presence in Northern Ireland waters with the disbandment of the
Northern Ireland Squadron. The Royal Navy's main presence is
HMS Hibernia, which serves as the HQ of the
Royal Naval Reserve's Ulster Division. ==Orders of battle==