During the night of April 9, 1918, the Germans made a strong assault on the French lines near Hangard-en-Santerre. The French retaliated with a counterblow that drove the enemy back in disorder. The village changed hands repeatedly, but early in the morning of April 10, 1918, the French gained possession of the place and of a cemetery near by, and established themselves strongly in the new positions.
All day long on April 11, 1918, the Germans were hurling great masses of troops against the British lines on the northern front, from La Bassée to the Ypres-Commines Canal southeast of Ypres. As the result of these heavy assaults Haig's troops were forced back north of Estaires and Steenwerck. The evacuation of Armentières followed. The German advance on the previous day between Warneton and the Lys on the north and their drive to the south of Armentières had subjected the place to attack from three sides. For the British to attempt holding the town under these conditions would have caused a useless sacrifice of troops. Armentières had no military importance, but the Messines-Wytschaete Ridge and the Passchendaele Ridge to the north of it were of great value. As long as these positions held out the British lines were safe. The Germans were confronted with the same situation that prevailed on the Somme front. The German push toward Amiens had been held up by the British possession of the Heights of Vimy and of the Notre-Dame-de-Lorette. These formed the hinge on which the whole British line swung as it moved westward. The same thing was happening in the north. The British center had given way under the fury of the German attacks, but the flanks held fast. On the north the Messines Ridge blocked the way of the German advance. For in case of a westward push both German flanks would be in great danger from this bastion which commanded the entire field of maneuver. Their front and rear as well as flanks would be subjected to destructive artillery fire from this ridge which therefore became the center of the fighting in the north.
The Germans recognizing the supreme importance of the ridge made determined and valiant efforts to capture the position. They launched one attack after another that were costly and brought no results. They entered the British lines in the village of Messines, but were promptly driven out in a brilliant counterattack and the important positions remained in British hands.
In the area west and northwest of Armentières the British troops were forced back in the fighting that continued throughout the day on April 12, 1918. The British retired to the neighborhood of the railway south of Bailleul, where the heaviest fighting continued without respite. The Germans captured Merville and drove the British forces operating near Ploegsteert to retire to new positions in the neighborhood of Neuve Église.
In the Hangard-en-Santerre sector of the French front to the southeast of Amiens the struggle was prolonged throughout the day. The Germans attacked with large forces, but the French held their own until late in the day, when the enemy, reenforced by fresh troops in considerable numbers, gained a portion of Hangard, while the French still held on to the western part of the town. In the Noyon sector the Germans were active with their artillery, but attempted no infantry attacks. Rheims, the martyred city, was again bombarded, with the result that a number of buildings were fired, especially in the vicinity of the cathedral.
During the night of April 12-13, 1918, the Germans made a determined drive for Neuve Église, three miles southwest of Messines, and after a prolonged struggle occupied the village. The British vigorously counterattacked in the morning and drove the enemy out, capturing a battalion commander and a number of prisoners. There was hard fighting at other points on the British front, the Germans losing ground at Festubert. On the French front all enemy attacks broke down. Northwest of Orvilles-Sorel French forces broke into the German line on a front of three quarters of a mile and won a strip of territory.
The Germans continued to bring up fresh divisions into the Messines sector, until twenty-three divisions were engaged. Neuve Église was wrested from the British during the night of April 14, 1918. Seven attacks were made on the British lines near Merville, only one of which pushed back the British line and was successful in gaining ground. The British in a dashing counterattack drove out the Germans and reoccupied the line. Bailleul and the neighborhood were the scene of violent fighting. The Germans seemed determined to carry the place at any cost. The town, which contained many handsome buildings, was reduced to a mass of ruins. The German pressure forced the British to evacuate the town in the night of April 15, 1918, after they had been driven from the heights to the south and southeast. The British troops fell back on the east and west line north of Wulverghem and Bailleul.
On this date (April 15, 1918) the Germans made other notable gains. Attacking the British on a nine-mile front, Haig's men were driven from Wytschaete and most of the Messines Ridge positions were taken. It will be recalled that this famous ridge was captured by the British from the Germans on June 7, 1917, after elaborate mining preparations had been made and 1,000,000 pounds of high explosives were used in blowing up the heights.
Intense fighting continued all day long on April 16-17, 1918, about the Messines Ridge and the Passchendaele Ridge to the north, forcing the British to retire to their lines east of Ypres.
In the Hangard sector on the French front, where since the beginning of the offensive the Germans had been hammering away in an effort to get astride the railway connecting Amiens with Clairmont, the British carried out a highly successful operation. At daybreak on April 17-18, 1918, along a front of about five miles between Thennes and Mailly-Renneval, the French launched a dashing assault that resulted in the capture of over 600 prisoners and the seizure of some important points which the enemy occupied. The ground over which the French had to charge had been transformed by recent rains into heavy mud into which the attackers sank at times up to their knees, but they pushed on undismayed. The commanding heights on the northern flank were carried amid victorious cheers. In the center bodies of infantry penetrated Senecat Wood and cleared up the gun emplacements which defended the approaches to Castel. Pressing forward, the French infantry established themselves on the outskirts of the town and prepared for an assault on the place.