The 42nd Battalion was authorized on 7 November 1914 and embarked for Great Britain on 10 June 1915.

It disembarked in France on 9 October 1915, where it fought as part of the 7th Canadian Brigade, 3rd Canadian Division in France and Flanders until the end of the war.

Private (later Lieutenant) Thomas Dinesen was awarded the Victoria Cross for his actions on 12 August 1918 at Parvillers, France.

[2] The novelist Will R. Bird was a member of the battalion, and wrote two books of memoirs on his war experiences: And We Go On and Ghosts Have Warm Hands.

The 42nd Battalion was awarded the following battle honours: The 42nd Battalion (Royal Highlanders of Canada), CEF, is perpetuated by The Black Watch (Royal Highland Regiment) of Canada.