WWI: Battle of Lys

7th April 1918

The battle opened on the evening of 7 April, with a heavy German artillery barrage against the southern part of the Allied line (between Armentières and Festubert.) The barrage continued until dawn on 9 April.

The Sixth Army then attacked with eight divisions. The centre of the attack struck the Portuguese divisions, which crumbled. The British 55th Division (south of the Portuguese) pulled back its northern brigade, and despite numerous further attacks held its ground for the rest of the battle. The British 40th Division (to the north) was outflanked and attacked from the rear and fell back to the north.

Horne committed his emergency reserves to stem the German breakthrough, but they too were defeated. The Germans broke through 15 km of front and advanced up to 8 km, the most advanced probe reaching Estaires on the Lys. There they were finally halted by British reserve divisions.