Lieutenant-General Sir Edwin Alfred Hervey Alderson, KCB was a senior British Army officer who served in several campaigns of the late nineteenth and early twentieth centuries. From 1915 to 1916 during the First World War he commanded the Canadian Expeditionary Force on the Western Front, during which time it saw heavy fighting.

The Actions of St Eloi Craters from 27 March to 16 April 1916, were local operations in the Ypres Salient of Flanders, during the First World War by the German 4th Army and the British Second Army. Sint-Elooi is a village about 5 km (3.1 mi) south of Ypres in Belgium. The British dug six galleries under no man's land, placed large explosive charges under the German defences and blew them at 4:15 a.m. on 27 March. The 27th Division captured all but craters 4 and 5. The 46th Reserve Division counter-attacked but the British captured craters 4 and 5 on 30 March. The Canadian Corps took over, despite the disadvantage of relieving troops in action.