The steady pressure of the Allies fin ally culminated in a terrific attack de livered by the British, on April 9, 1917, N. and S. of Arras. German posi tions were taken to a depth of two and three miles, but most notable was the capture of the famous Vimy Ridge, which dominated the coal fields of Lens. During two days over 11,000 Germans were taken prisoners. With unabated energy, however, the British pushed on, reaching a point within five miles of Arras. Within the following week they advanced another three miles, and were now within striking distance of Lens, an important mining center, which had been held by the Germans since the autumn of 1914. On April 14 the British guns took up positions which enabled them to hurl tons of explosives into the middle of the city. On that same day the British infantry pushed its way into the suburbs of Lens, the Germans resisting with the utmost vigor.
The object of Field Marshal Haig in attacking Lens was to turn La Bassee from the S. for La Bassee and Lens formed the principal outworks of Lille, which was the key to the whole German position in Flanders. With these two places in their possession, the British would practically have Lille at their mercy.
On April 16, 1917, the French launched a general attack on a front along twenty five miles, between Soissons and Rheims. Everywhere they met with success, caps turing the German first line positions along the entire front. This victory was achieved along the historic line of the Aisne, to which the Germans had re treated after the battle of the Marne. Within a few days the French had ad vanced on both sides of Rheims, so that that city now formed the point of a salient.
For a week or more the Allied offen sive slowed down. But when it was again resumed, on April 23, progress was achieved more slowly. The Ger mans had brought heavy re-enforce ments from the eastern front. They now launched some heavy counterattacks against the French in the Champagne sector, but the few gains they at first made cost them dearly in their heavy losses of men. Early in May the French struck back, and again gained ground, notably the village of Craonne, on a height on the E. end of the Chemin des-Dames.
On May 9, 1917, severe fighting began again in the neighborhood of Bullecourt. Three days later the British entered this important town and partially occupied it. In their attempt to retake this British gain, the Germans precipitated some of the deadliest fighting which had as yet taken place on the western front.
The Germans fought desperately, for here was their Hindenburg line, which they determined must remain intact at all costs.
Battle of Messines in the morning of June 7, 1917, there oc curred one of the most spectacular events which had ever taken place in any theater of the war.
For about two weeks the British had been bombarding the strong German salient S. of Ypres. Here the Allies had, for two years, been at the mercy of the German guns on Messines Ridge, one of the strongest points held by the Ger mans along the entire western front. For nearly two years the British engi neers had been patiently boring under this position. Early in the morning of June 7 the nineteen miles which had been planted under the ridge were ignited, and almost the entire top of the eminence rose skyward in a burst of smoke and flame. Hardly had the debris settled down when the British leaped into this wide gap in the German lines and within half an hour ten miles of the German first lines had been captured. Large quantities of guns, and 7,000 prisoners were taken. The Germans had now lost their last position which commanded the British lines. Together with their pre vious successes, by this victory they had now entirely changed the military posi tion in Belgium. The areas gained amounted to a front of nine miles, five miles deep.
During July extremely heavy fighting took place in the Verdun sector. The Germans attacked heavily, but the French were well able to hold them back.
Around Lens the British continued hammering away. Their successes here and elsewhere, however, were somewhat counterbalanced by the success attend ing the Germans in their attack on the British lines N. of Nieuport, on the Belgian coast. Here the British were compelled to give ground. This tempo rary gain, however, terminated three weeks later when, on July 31, the British and French launched an attack on a gigantic scale along a front of twenty miles, from Dixmude on the N. to Warneton on the S. In their turn the Germans were compelled to retire along a front of fifteen miles.
During the rest of the summer the Allies continued their offensive tactics, surging ahead for a week or two, then pausing to consolidate their gains. Little by little the Canadians, who were at tacking Lens, closed their grip on that city and were firing into the very heart of the business section. It was a steady process of eating into the German posi tions, breaking off a piece here, tearing down a defense there.