April 24th , 1633
In April 1633, Sir John Hepburn was granted a warrant by Charles I to recruit 1200 Scots for service with the French army in the 1618–1648 Thirty Years War. The nucleus came from Hepburn’s previous regiment, which fought with the Swedes from 1625 until August 1632, when Hepburn quarrelled with Gustavus Adolphus.
It absorbed other Scottish units in the Swedish army, as well as those already with the French and by 1635 totalled around 8,000 men.
The Royal Scots
The Royal Scots (The Royal Regiment), once known as the Royal Regiment of Foot, was the oldest and most senior infantry regiment of the line of the British Army, having been raised in 1633 during the reign of Charles I. The regiment existed continuously until 2006, when it amalgamated with the King’s Own Scottish Borderers to become the Royal Scots Borderers, which merged with the Royal Highland Fusiliers (Princess Margaret’s Own Glasgow and Ayrshire Regiment), the Black Watch, the Highlanders (Seaforth, Gordons and Camerons) and the Argyll and Sutherland Highlanders to form the Royal Regiment of Scotland.