Bomberg was commissioned in 1917 by the Canadian War Memorials Fund to commemorate an incident in which a company of Canadian soldiers dug tunnels under the German trenches to lay explosives for a surprise assault on the enemy defences at Ypres, in France. He produced a series of drawings showing the complex structures of struts, girders and pulleys that formed part of the underground environment. Here, his tiny figures are dwarfed by these dominant structures.