The artillery preparation began at 9.15 a.m. on June 1, and at noon the first assaulting wave entered the front-line trenches. The battle died down for a few minutes in the evening, only to break out again during the night. The Germans succeeded in crushing in the front to a depth of some 700 yards in the direction of Zillebeke, but the next day a portion of the lost ground was retaken by the Canadians. [Illustration: THE FLANDERS BATTLEFIELD IN WINTER] On June 6, a fresh assault began, preceded by the usual bombardment, and further assisted by mine explosions. The front line trenches to the north of Hooge were lost; but on the 13th the valiant Canadians, who had previously recaptured the original positions abandoned on June 1, resumed the offensive, and re-established the lines from the southern part of Sanctuary Wood to a point 1,000 yards north of Hill 60. Throughout the days of June 26 and 28 there was an extremely violent bombardment, to which the British guns replied effectively. The Germans, whose losses from the attacks and this artillery fire were very heavy, declared: "_Belgium will be our grave._" These were the last operations in which the enemy took the offensive. All their efforts had failed, whether their object had been to turn the left flank of the Allies, to break the lines around Ypres, or merely to take the town. =THE ALLIED OFFENSIVE OF 1917= _Series of powerful attacks with limited objectives. From June to October, the stages of the offensive were punctuated by breathing spaces, during which the conquered ground was consolidated, in view of counter-attacks, and the artillery brought up, to prepare the following attack._ =Preliminary Operations= =The Capture of Messines Ridge by the British= (June 7, 1917.) From July, 1916, to May, 1917, the Ypres sector remained comparatively quiet. There were few attacks on either side, but the guns thundered day and night. It may be said that the British were "trying their hand." In June, 1917, certain at last of their strength, they made their first big effort, and step by step, in accordance with a carefully worked-out plan, they completely liberated Ypres by a series of offensives lasting four months, and broke the iron circle which, for two years, had been strangling the town. For several months before the battle, the attack on Messines Ridge had been carefully planned by means of a model in relief, situated in the open air and covering an area about equal to that of a tennis court. Here were reproduced in relief all the contours and peculiarities of the ground. Everything, down to an isolated tree trunk, was reproduced. British effort took definite shape for the first time on June 7. The attack, planned by Sir Douglas Haig, had for its objective the capture of the crests between Wytschaete and Messines, which the Germans had seized on November 1, 1914.