The regiment's history began in 1678, when three independent troops of Scots Dragoons were raised. In 1681, these troops were regimented to form The Royal Regiment of Scots Dragoons, numbered the 4th Dragoons in 1694.
Mounted on grey horses, they were already being referred to as the Grey Dragoons. In 1707, they were renamed The Royal North British Dragoons (North Britain then being the envisaged common name for Scotland), but were already being referred to as the Scots Greys.
In 1713, they were renumbered the 2nd Dragoons as part of deal between the establishments of the English and Scottish Army when they were being unified into the British Army. They were also sometimes referred to, during the first Jacobite uprising, as Portmore's Dragoons. In 1877, their nickname was finally made official when they became the 2nd Dragoons (Royal Scots Greys), which was inverted in 1921 to The Royal Scots Greys (2nd Dragoons). They kept this title until 2 July 1971, when they amalgamated with the 3rd Carabiniers, forming the Royal Scots Dragoon Guards. (Source Wikipedia)
At the Battle of Waterloo their charge (which was achieved out of necessity, at a canter!) was immortalised, and famously, Sergeant Charles Ewart captured the eagle of the French 45e Régiment de Ligne (45th Regiment of the Line)