The Black Watch was raised in the wake of the 1715 Jacobite rebellion when companies of trustworthy Highlanders were raised from loyal clans, Campbells, Grants, Frasers, Munros. Six companies were formed from 1725 and stationed in small detachments across the Highlands to prevent fighting between the clans, deter raiding and assist in enforcing the laws against the carrying of weapons. In 1739 King George II authorised the raising of four additional companies and these all to be formed into a Regiment of the Line of the regular army with the Earl of Crawford as the Colonel. The men were to be 'natives of that country and none other to be taken'.

The first muster of the new Regiment took place near Aberfeldy the following year and is commemorated by a monument in the form of a soldier dressed in the uniform of those days. Today's Black Watch were formed on 1 July 1881 when the 42nd and 73rd Regiments were combined into a single new regiment titled The Black Watch (Royal Highlanders). The title 'Black Watch' was derived from the dark colour of the tartan worn by the Regiment and their original role which was to 'watch' the Highlands.

At the outbreak of war in 1914 there were seven Black Watch Battalions, two regular battalions, a special reserve battalion and four territorial battalions. The 1st Battalion was based in Aldershot in England and the 2nd Battalion in India.