In 1965, the regiment was reduced to nil strength and placed on the Supplementary Order of Battle.
[1][2] On 10 April 1885, the 47th Frontenac Battalion of Infantry mobilized a company for active service that served as part of the Midland Battalion in the Alberta Column of the North West Field Force.
[2] On 6 August 1914, the Cobourg Heavy Battery was placed on active service and during the fall of 1914, the battery served in Lévis, Quebec, and Vancouver, British Columbia, providing coastal artillery support.
On 16 September 1915, the battery disembarked in France where it provided heavy artillery support as part of the 2nd Brigade, CGA, CEF in France and Flanders until the end of the war.
After its arrival in the UK, on 7 October 1916, the battalion's personnel were absorbed by the 95th Battalion, CEF, where it provided reinforcements for the Canadian Corps in the field.