The attack began on Tuesday, 9th April. A Portuguese division south of the Lys was driven in at the first thrust, and through the gap the enemy streamed in. At a quarter-past ten that morning he was more than a mile to the rear of the division holding the left of the gap, which was accordingly compelled to retreat. On the right of the gap, covering Béthune, lay the 55th West Lancashire Division. The story of the Lys is a story of the successful defence of key-points against critical odds, and Givenchy, where the men of West Lancashire stood, was most vital, for unless it fell Béthune could not be taken, and unless Béthune were captured at once the enemy attack would be cramped into too narrow a gate. The 55th Division did not yield though outnumbered by four to one. They moved back their left flank but they still covered Béthune, and their right at Givenchy stood like a rock. By noon the enemy was in the ruins of Givenchy; in the afternoon the Lancashire men had recovered them; in the evening they were again lost, and in the night retaken. This splendid defence was the deciding event in the first stage of the battle. It was due, said the official report, "in great measure to the courage and determination displayed by our advance posts. Among the many gallant deeds recorded of them, one instance is known of a machine-gun which was kept in action although the German infantry had entered the rear compartment of the pill-box from which it was firing, the gun team holding up the enemy by revolver fire from the inner compartment." Next day, 10th April, a new German army attacked north of the Lys, captured Messines, and was pouring over the Wytschaete crest. But at Wytschaete stood the 9th Division, which we have previously seen in action on the Somme at Marrières Wood. There its South African Brigade had been completely destroyed, but a new one had been got together, and this second showed all the heroism of the first. That night they retook Messines, and during the evening cleared the Wytschaete Ridge. That stand saved the British northern flank and gave its commander time to adjust his front. For thirty hours the Germans were held up on that ridge, and when they finally advanced the worst danger was past.