The regiment was formed in 1922 as part of a reduction in the army's cavalry by the amalgamation of the 3rd Dragoon Guards and the Carabiniers, to form the 3rd/6th Dragoon Guards. Both regiments were based in India at the time of their amalgamation; the newly formed regiment departed in 1925 for Britain. It regained its carabinier association in 1928, when it was renamed the 3rd Carabiniers . The 3rd Carabiniers was posted to Sialkot in India in 1936 and began its mechanisation process, changing its horses for armoured vehicles, in 1938.
When the war began in September 1939, the 3rd Carabiniers was still based in India. In 1941, a cadre from the regiment was used to form the 25th Dragoons, which saw service in Burma; it was disbanded in India in 1947. Now equipped with the M3 Leemedium tank, the regiment was sent to North-East India with the 254th Indian Tank Brigade in December 1943. It took part in the Battle of Imphal, which began in late March 1944 after the Japanese launched the U-Go offensive. On 20 March, around Tamu, six of the regiment's tanks clashed with six Japanese Type 95 Ha-Go tanks, destroying five of them and capturing the other. Later, in the battle to retake Nunshigum Ridge on 13 April, tanks from the regiment's 'B' Squadron supported the 1/17th Dogras in fierce fighting that dislodged the Japanese defenders. The 3rd Carabiniers, operating usually at squadron level or lower, took part in the successful advance deep into occupied Burma, taking part in an intense action at Kennedy Peak. Early 1945 saw the regiment engaged in fighting at Shwebo and Sagang; it took part in the capture of Ava and Mandalay in March, and later around the Irrawaddy River.
Post-World War II
After the war's official end in September, the regiment was based at Ahmednagar in India up until the British withdrawal. The regiment's departure came in January 1947, when it embarked aboard the Highland Princess at Bombay. The 3rd Carabiniers was posted to the British Army of the Rhine in West Germany in March 1952. The regiment was based in Osnabrück, remaining there until May 1959. After that, it moved to Catterick, England, but its stay there was short, as it joined the Strategic Reserve at Tidworth in July 1960. In July 1961, the regiment deployed its 'C' Squadron to Kuwait as part of a British force charged with deterring Iraq from fulfilling its threats to annex it. A return to West Germany came the following year, when it joined the 20th Armoured Brigade in Detmold. Having been armed with tanks since the early 1950s, the regiment was re-roled to a reconnaissance unit in 1967, first operating the Ferret scout car. Deployments to the British military installations in Libya and Cyprus followed in 1968. A brief posting to Münster, West Germany took place in 1969 before moving to Herford, West Germany. On 2 July 1971, the regiment amalgamated with the Royal Scots Greys, forming the Royal Scots Dragoon Guards.
The 3rd Carabiniers possessed a total of 62 battle honours, of which 49 were inherited from its predecessor units and were earned prior to the regiment's formation in 1922. During the Second World War, the amalgamated regiment received 13 battle honours. The full list of battle honours held by the regiment are:
