At the end of the war, the Regiment concentrated in Gluckstadt and after a refit with Comet Tanks in Belgium returned to Schleswig before moving to Berlin to rejoin the 7th Armoured Division. In March 1946, the Regiment returned to Schleswig Holstein, and shortly afterwards moved to Hobart Barracks, Detmold where it remained for eight years. During this period it was the first regiment to be equipped with the Mark 3 Centurion and was the first to receive National Servicemen.
In September 1952, the Regiment moved to Tidworth where it prepared for embarkation to Korea and sailed from Liverpool on 27 October aboard the 'Empire Halladale'. The First landed in Korea on 6 December 1952, and within 24 hours of arrival at the front had taken over in the line from the 5th Royal Inniskilling Dragoon Guards. Because of the static nature of the war, all the tanks were dug into pits to protect their suspension and lower parts from enemy fire. Their main task was to dominate 'No Mans Land' by engaging every movement, observation post and occupied trench. The tanks also supported raids carried out by the infantry. During the six months that the Regiment was in the line, the crews fired nearly 26,000 rounds of HE. Supply was no mean feat either in the snow and sub-zero of winter or the mud of the Summer wet season. The Commonwealth division, of which the First was a part, did not yield any ground in spite of the most determined efforts by the enemy. The Regiment handed over to the 5th Royal Tank Regiment and embarked for the Canal Zone on 15 December 1953.
The Regiment arrived at Shandur in the Suez Canal Zone on 5 January 1954. As part of 25 Armoured Brigade its task was to protect British interests in the Zone. After the signing of the agreement to evacuate Egypt, the First moved north to Genifa and finally embarked for England from Port Said in August 1955. Following the decision to attack Suez, the Regiment sailed in late October 1956 for the Canal Zone, but were halted at Malta when the Suez operations ended. On the Regiment's return to England early in 1957, it was posted to Hong Kong, where it was stationed at Sek Kong as part of the 48th Gurkha Infantry Brigade. Whilst serving in Hong Kong the First was the last regular regiment to be equipped with Comet tanks. In July 1960 it handed over to 17th/21st Lancers after being re-equipped with Centurions and moved to Hohne, West Germany, where it stayed until November 1965. The Regiment then sailed to the Middle East and served in Little Aden whilst 'B' Squadron became the independent tank squadron in Hong Kong. During the 12 month tour with 24 Infantry Brigade, the First was engaged in internal security operations in Little Aden and the area west and north of the Aden Protectorate up to the Yemen border. Whilst serving in this role, the Regiment was re-equipped with Saladin and Ferret armoured cars. In Hong Kong 'B' Squadron sent detachments to join units in action in Malaysia as well as being involved in IS duties during local riots and border patrols.
In January 1967, the Regiment moved to Catterick as the RAC Training Regiment and two years later was posted to Osnabruck. West Germany as an Armoured Regiment. Between January and June 1972, the Regiment provided two squadrons for employment as infantry on IS duties in Northern Ireland, and in May 1973 took over from the 16th/5th Lancers as the resident Armoured Car Regiment in Northern Ireland being stationed at Omagh. The role of the Regiment during its 18 month tour was to support the Royal Ulster constabulary in maintaining law and order in Police Division L and M.
The majority of the work entailed the patrolling of these Divisions with particular importance being attached to the border with the Irish Republic. The Regiment came under small arms fire, rocket and mortar attacks and ambushes involving Improvised Explosive Devices (IED). As a result of two IEDs, 2 soldiers, a dog handler and an Ammunition Technical Officer, attached to the Regiment were killed.
At the end of this tour in November 1974, the Regiment was posted to Tidworth with Squadrons based in Hong Kong and Cyprus. The Squadron in Cyprus was involved in duties resulting from the Turkish invasion of North Cyprus.
After returning to UK in October 1975 the First moved to Herford in April 1976 as the 1 (BR) Corps covering Force. In May 1977 the Regiment provided 2 squadrons for IS duties in Londonderry for 4 months. On the reorganisation of January 1978 the Regiment became the 2 Armoured Division Armoured Reconnaissance Regiment.
The Regiment returned to the UK in 1982 and spent two years in Bovington. It then moved to Hildesheim in 1985 but had one squadron in Northern Ireland for six months.
After eight years in Hildesheim the First moved to Tidworth in 1993. However, on arrival they immediately amalgamated with 4 RTR who had moved to Tidworth from Osnabruck.
The newly amalgamated First set about establishing new roots and bringing many of the old 4 RTR traditions onto their books, primarily the Pipes and Drums and the Rose Tartan.
The First returned to Germany in 1996 and established themselves in Paderborn. The noteworthy event at this time was that on handing in their Chieftains to Luggershall they were recognised as the last RAC Regiment to operate on Chieftain. In Germany they were equipped with Challenger 1.
In early 1998 the Strategic Defence Review was announced, the First was nominated to form the Army element of the Joint Nuclear, Biological and Chemical Regiment (JNBCR).
The First moved from Paderborn to RAF Honington and was operational in its new role by 31 December 1999, since their arrival in Honington they have had an independent troop permanently located in Kuwait. One sub-unit, A Squadron, was tasked to provide the armoured squadron as part of the Combined Arms Training Centre Battle Group (CATC BG) at Warminster, they are equipped with Challenger 2. The Honington element of the Regiment are equipped with the Fuchs Armoured Car and Box Bodied PBDS equipment. The Regiment has had elements deployed on Operations in Iraq and Afghanistan. It has also carried out Training in Canada which has included the deployment of their Armoured Squadron.