Battle of Messines (Mesen) near Ypres; West Flanders;21 May - 7 Juni 1917 (victory of the Allied troops after major offensive with artillery fire and mines in tunnels underneath the German positions)."R.E.'s Mine and Counter-Mine Messines Ridge; which dominated Ypres; blown up and stormed; June 7th. 17" (Tunnellers of the British Royal Engineers Corps drilling underground).Photo (part of a stereoscopical photo);c. May / June 1917.From a series: The Great War.