In 1678 three companies of dragoons were raised in Scotland during a government campaign to suppress the Covenanters. Dragoons operated as mounted infantry, able to cover rough terrain and dismount to fight when necessary. A further three companies were recruited in 1681 to form a regiment of dragoons under the command of Lieutenant-General Thomas (Tam) Dalyell of the Binns. King William III conferred the title 'Royal Regiment of Scots Dragoons' in 1692.
The name 'Royal Scots Greys' perhaps originates in Tam Dalyell's time when he may have been granted royal permission for his regiment to wear grey cloth rather than the national colour red. By 1694 the Scots Dragoons were mounted on grey horses which could also explain the regimental association with the colour.