New German Submarine War Zone of February 1, 1917 207 The Entire Western Front, August 1, 1917 220 The German Retreat on the Western Front, March 18, 1917 233 Taking of Vimy Ridge by the Canadians, April 9 and 10, 1917 240 The French Offensive on the Craonne Plateau, Champagne 257 The Taking of Messines Ridge, June 7, 1917 266 The Somme Battle Front, August 1, 1917 283 The Russian Offensive and Retreat in Galicia 446 The Entire Eastern Battle Front, August 1, 1917 450 PART I--WESTERN FRONT--SOMME AND VERDUN CHAPTER I FRENCH AND BRITISH ADVANCES The first month of the Allied offensive on the Somme front closed quietly. The British and French forces had every reason to feel encouraged over their successes. In the two thrusts since July 1, 1916, they had won from the Germans nearly twenty-four square miles of territory. Considering the extent to which every fraction of a mile was fortified and defended, and the thoroughness of the German preparations to make the district impregnable, the Allied gains were important. As a British officer said at the time, it was like digging badgers out of holes--with the proviso that every badger had machine guns and rifles at the hole's mouth, while the approach to each was swept by the fire from a dozen neighboring earthworks. It was estimated that in the first month of the Allied offensive on the Somme the German casualties amounted to about 200,000 men, while the Anglo-French forces lost less than a fourth of that number. The Allies claimed to have captured about 13,000 prisoners and between sixty and seventy field guns, exclusive of machine guns and the smaller artillery. With the capture of Pozieres it might be said that the second phase of the Battle of the Somme was concluded. The Allied forces were well established on the line to which the second main "push" which began July 14, 1916, was directed. During the first three days of August, 1916, comparative quiet prevailed along the Somme front, and no important offensive was attempted by either side. Minor fighting continued, however, every day, and during the nights the English positions were heavily bombarded by the German guns.