The Scots Guards is a regiment

Regiment

A regiment is a major tactical military unit, composed of variable numbers of batteries, squadrons or battalions, commanded by a colonel or lieutenant colonel...

 of the Guards Division

Guards Division

The Guards Division is an administrative unit of the British Army responsible for the administration of the regiments of Foot Guards and the London Regiment.-Introduction:...

 of the British Army

British Army

The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...

, whose origins lie in the personal bodyguard of King Charles I of England and Scotland. Its lineage can be traced as far back as 1642, although it was only placed on the English Establishment (thus becoming part of what is now the British Army) in 1686.

The Scots Guards is ranked as the third regiment in the Guards Division

Guards Division

The Guards Division is an administrative unit of the British Army responsible for the administration of the regiments of Foot Guards and the London Regiment.-Introduction:...

; as such, Scots Guardsmen can be recognised by having the buttons on their tunics spaced in threes.