Somme, Battle of the

Allied offensive in World War I July-November 1916 on the River Somme in northern France, during which severe losses were suffered by both sides. It was planned by the Marshal of France, Joseph Joffre, and UK commander-in-chief Douglas Haig; the Allies lost over 600,000 soldiers and advanced approximately 8 km/5 mi (13 km/8 mi at its furthest point). It was the first battle in which tanks were used. The German offensive around St Quentin March-April 1918 is sometimes called the Second Battle of the Somme.

The first Battle of the Somme was launched on 1 July by British and French troops against well-entrenched German dug-out positions. The British had made obvious preparations for the assault, including a week-long artillery bombardment. Consequently, the Germans were able to reinforce their defences and the British suffered the heaviest casualties in their history; 19,240 men were killed on the first day. In spite of this, the attack continued and several small gains were made - the German line was almost breached on 14 July. After a lull, the battle started again on 15 September when tanks were used for the first time; some 47 tanks were available to the Allies of which most broke down. This attack made some progress but when the battle finally died away in mid-November the total Allied gain was about 8 km/5 mi at a cost of 625,000 Allied and about 680,000 German casualties.

The second Battle of the Somme on 21 March 1918 was the first act of the German Spring Offensive; it was intended to capture Amiens and split the French and British armies. The attack was initially successful, forcing the Allies to fall back and the Germans were within a few miles of Arras before they were finally held.