September was the most costly month of the battle for the German armies on the Somme, which suffered about 130,000 casualties. On 18 September, the Quadrilateral, where the British advance had been frustrated on the right flank, was captured.Īrrangements were begun immediately to follow up the success which, after supply and weather delays, began on 25 September at the Battle of Morval, continued by the Reserve Army next day at the Battle of Thiepval Ridge. The Fourth Army crossed Bazentin Ridge, which exposed the German rear-slope defences beyond to ground observation. The British attempt to advance deeply on the right and pivot on the left failed but the British gained about 2,500 yd (1.4 mi 2.3 km) in general and captured High Wood, moving forward about 3,500 yd (2.0 mi 3.2 km) in the centre, beyond Flers and Courcelette.

On 16 September, Jagdstaffel 2, a specialist fighter squadron, began operations with five new Albatros D.I fighters, which had a performance capable of challenging British and French air supremacy for the first time in the battle. Tanks were used in battle for the first time the Canadian Corps and the New Zealand Division fought their first engagements on the Somme. The German defensive success on the British right flank made exploitation and the use of cavalry impossible. The infliction of many casualties on the German front divisions and the capture of the villages of Courcelette, Martinpuich and Flers had been a considerable tactical victory. The Anglo-French attack of 15 September began the third period of the Battle of the Somme but by its conclusion on 22 September, the strategic objective of a decisive victory had not been achieved.

The Battle of Flers–Courcelette (, 15 to 22 September 1916) was fought during the Battle of the Somme in France, by the French Sixth Army and the British Fourth Army and Reserve Army, against the German 1st Army, during the First World War.

First tank battle in ww1