The Battle of the Somme, also known as the Somme offensive, was a battle of the First World War fought by the armies of the British Empire and French Third Republic against the German Empire. It took place between 1 July and 18 November 1916 on both sides of the upper reaches of the Somme, a river in France. The battle was intended to hasten a victory for the Allies. More than three million men fought in the battle and one million men were wounded or killed, making it one of the deadliest battles in human history.

The French and British had committed themselves to an offensive on the Somme during the Chantilly Conference in December 1915. The Allies agreed upon a strategy of combined offensives against the Central Powers in 1916 by the French, Russian, British and Italian armies, with the Somme offensive as the Franco-British contribution. Initial plans called for the French army to undertake the main part of the Somme offensive, supported on the northern flank by the Fourth Army of the British Expeditionary Force (BEF). When the Imperial German Army began the Battle of Verdun on the Meuse on 21 February 1916, French commanders diverted many of the divisions intended for the Somme and the "supporting" attack by the British became the principal effort. The British troops on the Somme comprised a mixture of the remains of the pre-war army, the Territorial Force and Kitchener's Army, a force of wartime volunteers.

On the first day on the Somme (1 July) the German 2nd Army suffered a serious defeat opposite the French Sixth Army, from Foucaucourt-en-Santerre south of the Somme to Maricourt on the north bank and by the Fourth Army from Maricourt to the vicinity of the AlbertBapaume road. The 57,470 casualties suffered by the British, including 19,240 killed, were the worst in the history of the British Army. Most of the British casualties were suffered on the front between the AlbertBapaume road and Gommecourt to the north, which was the area where the principal German defensive effort (Schwerpunkt) was made. The battle became notable for the importance of air power and the first use of the tank in September but these were a product of new technology and exceedingly unreliable.

At the end of the battle, British and French forces had penetrated 6 mi (10 km) into German-occupied territory along the majority of the front, their largest territorial gain since the First Battle of the Marne in 1914. The operational objectives of the Anglo-French armies were unfulfilled, as they failed to capture Pronne and Bapaume, where the German armies maintained their positions over the winter. British attacks in the Ancre valley resumed in January 1917 and forced the Germans into local withdrawals to reserve lines in February before the scheduled retirement by about 25 mi (40 km) in Operation Alberich to the Siegfriedstellung (Hindenburg Line) in March 1917. Debate continues over the necessity, significance and effect of the battle.

The Battle of Delville Wood (15 July – 3 September 1916) was a series of engagements in the 1916 Battle of the Somme in the First World War, between the armies of the German Empire and the British Empire. Delville Wood (Bois d'Elville), was a thick tangle of trees, chiefly beech and hornbeam (the wood has been replanted with oak and birch by the South African government), with dense hazel thickets, intersected by grassy rides, to the east of Longueval. As part of a general offensive starting on 14 July, which became known as the Battle of Bazentin Ridge (14–17 July), General Douglas Haig, Commander of the British Expeditionary Force, intended to capture the German second position between Delville Wood and Bazentin le Petit.

The attack achieved this objective and was a considerable though costly success. British attacks and German counter-attacks on the wood continued for the next seven weeks, until just before the Battle of Flers–Courcelette (15–17 September), the third British general attack in the Battle of the Somme. The 1st South African Infantry Brigade made its Western Front début as part of the 9th (Scottish) Division and captured Delville Wood on 15 July. The South Africans held the wood until 19 July, at a cost in casualties similar to those of many British brigades on 1 July.

The village and wood formed a salient, which could be fired on by German artillery from three sides. The ground was a rise from Bernafay and Trônes woods, to the middle of the village, neither village or wood could be held without possession of the other. After the Battle of Bazentin Ridge, the British tried to advance on both flanks to straighten the salient at Delville Wood, to reach good jumping off positions for a general attack. The Germans tried to eliminate the salient and to retain the ground, which shielded German positions from view and overlooked British positions. For the rest of July and August, both sides fought for control of the wood and village but struggled to maintain the tempo of operations.

Wet weather reduced visibility and made the movement of troops and supplies much more difficult; ammunition shortages and high casualties reduced both sides to piecemeal attacks and piecemeal defence on narrow fronts, except for a small number of bigger and wider-front attacks. Most attacks were defeated by defensive firepower and the effects of inclement weather, which frequently turned the battlefield into a mud slough. Delville Wood is well preserved with the remains of trenches, a museum and a monument to the South African Brigade at the Delville Wood South African National Memorial.