[4] Details of the 5th Regiment, Royal Highlanders of Canada, were placed on active service on 6 August 1914 for local protective duty.

The 13th Battalion (Royal Highlanders of Canada), CEF, was authorized on 1 September 1914 and embarked for Great Britain on 26 September 1914, disembarking in France on 16 February 1915, where it fought as part of the 3rd Infantry Brigade, 1st Canadian Division in France and Flanders until the end of the war.

The 42nd Battalion (Royal Highlanders of Canada), CEF, was authorized on 7 November 1914 and embarked for Great Britain on 10 June 1915, disembarking in France on 9 October 1915, where it fought as part of the 7th Infantry Brigade, 3rd Canadian Division in France and Flanders until the end of the war.

The 73rd Battalion (Royal Highlanders of Canada), CEF, was authorized on 10 July 1915 and embarked for Great Britain on 31 March 1916, disembarking in France on 13 August 1916, where it fought as part of the 12th Infantry Brigade, 4th Canadian Division until 9 April 1917 when it was withdrawn from the line after Vimy and was disbanded, its personnel used as replacements for other units.

This unit served in Canada in a home defence role as part of Atlantic Command until it was disbanded on 15 August 1943.

"E" Company was reduced to nil strength upon its personnel being incorporated into the 1st Canadian Highland Battalion for service in Germany with the North Atlantic Treaty Organization.

On 15 May 1952, it was reduced to nil strength, upon its personnel being absorbed by the 2nd Canadian Highland Battalion for service in Korea with the United Nations.

On 16 October 1953, it was redesignated the 1st Battalion, The Black Watch (Royal Highland Regiment) of Canada.

Ross, served in Korea as part of 25th Canadian Infantry Brigade following the armistice from 29 October 1953 to 3 November 1954.

It is a descendant of the 42nd Battalion Royal Highlanders of Canada Pipes and Drums, which was active during the First World War.

Bishop's College School Cadet Corps #2 has been affiliated with the Royal Highland Regiment of Canada since 1936.

[13] In early May each year, the Corps sends two platoons and the colour party to march with the Regiment in their Church Parade.

[13] Gallant Black Watch, a Scotch style march and two-step, was composed by Bert L. Billings and published in Toronto by Whaley, Royce & Co., c. 1906.