The Battle of Arras took place from 9 April to 16 May, 1917. It was fought by the British (First Army under Allenby, Third Army under Horne, Fifth Army under Gough) under the supreme command of General Haig against the heavily fortified line held by German Sixth and Second Armies. After a massive artillery bombardment, British managed to advance in heavy fighting for up to 4.5 miles in some places - one of the largest gains since the start of the trench warfare.

Casualties surpassed 150,000 for the British, 100,000 for the Germans. No strategic breakthroughs were achieved.