A Thanksgiving Service, attended by Canadian troops, being held in the Cambrai Cathedral (Notre-Dame de Grâce chapel)
Canadian Expeditionary Force albums - Unknown photographer
This image is available from the <a href="https://en.wikipedia.org/wiki/Archives_of_Ontario" class="extiw" title="en:Archives of Ontario">Archives of Ontario</a> under the  item reference code <b>C 224-0-0-10-39</b>