The 4th Battalion (Central Ontario) was raised at Valcartier in September, 1914, and the battalion left for the United Kingdom within weeks of establishment. After landing in France in February, 1915, the battalion was assigned to the 1st Canadian Infantry Brigade, 1st Canadian Division. As casualties mounted, the battalion was reinforced by the 3rd Canadian Reserve Battalion. The unit fought on the Western Front, remaining in France and Belgium until the end of the war.
The battalion returned to Canada in April, 1919 and disbanded in 1920.
Source: “4th Battalion (Central Ontario), CEF”. Wikipedia, https://en.wikipedia.org/wiki/4th_Battalion_(Central_Ontario),_CEF, accessed on June 24, 2020.