The 12th C.M.G. Coy. was attached to the 12th Infantry Brigade, 4th Canadian Infantry Division.
It landed in France on 12 August, 1916. It was formed from the MG Sections of the Infantry Battalions of the Brigade.
After being relieved from the Lens-St. Emile and Hill 70 sectors of the line on the night of 28 March, it moved to Springvale Camp, near Ecurin. On 29 March, it was amalgamated with the 11th C.M.G. Company to form No. 2 Company, 4th Bn, C.M.G.C..