|Commanders and leaders
| Joseph Joffre
|Crown Prince Rupprecht of Bavaria
|9 French and British divisions (initial)
20 divisions (final)
|18 divisions (final)
|Casualties and losses
27,809 (Aubers Ridge: 11,161, Festubert: 16,648)
The course of the fighting in 1914 had created a salient between Rheims and Amiens, from which the German armies menaced communications between Paris and northern France; at Noyon the Western Front as only 55 miles (89 km) from Paris. In the 200 miles (320 km) from Rheims to the North Sea, the German armies were supplied by rail from Cologne and Düsseldorf, along a southern line from Thionville to Longuyon, Mezières, Hirson and Valenciennes, which passed 12 miles (19 km) from Verdun. In the north lines ran for 200 miles (320 km) from the Rhine into the Douai plain and then through Valenciennes to Aulnoye, Douai, Cambrai and St. Quentin. A French advance eastwards in Artois could cut the lines supplying the German armies between Arras and Rheims. Local French operations had been conducted in Artois, Champagne and Alsace during November and December 1914, which led General Joseph Joffre, Generalissimo (Commander in Chief) and head of Grand Quartier Général (GQG) to continue the offensive in Champagne, to capture the southern rail supply route and to plan an offensive in Artois against the railway lines supplying the German armies from the north, to coincide with the operations in Champagne and then to cut German lines of retreat.
Joffre's strategy governed the Franco-British offensives in France and Belgium during 1915 and foreshadowed the plan which led to the victorious offensives of 1918. Field Marshal Sir John French, the commander of the British Expeditionary Force (BEF) agreed to co-operate with the French strategy. On 16 February Joffre disclosed a plan for the French Tenth Army to advance on a line from Arras north to Pont à Vendin and capture Vimy Ridge, assisted by British attacks from La Bassée against Aubers Ridge, which would confront the German Sixth Army with an attack on a front of 70 miles (110 km) and prepare the way for an exploitation into the Douai plain, where an advance of 10–15 miles (16–24 km) would cut the railways supplying the German armies as far south as Rheims.
A series of attacks was made by the French Tenth Army and the British First Army, in which the French attacked Vimy Ridge and the British attacked further north in the Battle of Aubers Ridge (9 May) and the Battle of Festubert from 15–25 May. The battle was fought during the German offensive at the Second Battle of Ypres (21 April – 25 May), which the Germans ended to reinforce the Artois front. The initial French attack on 9 May broke through in the centre and captured Vimy Ridge but reserve units had been assembled out of range of German artillery and were not able to reinforce the troops on the ridge before German counter-attacks forced them back about half-way to their jumping off points.
The attack of the British First Army at Aubers Ridge was a costly failure, in which a few footholds were gained in the German front line and lost overnight. Two German divisions in reserve opposite the British were diverted south, to reinforce the divisions opposite the French Tenth Army. The British offensive was suspended until 15 May at the Battle of Festubert and the French offensive from 15 May – 16 June was concentrated on the flanks to create jumping-off points for a second general offensive, which began on 16 June after numerous delays. The resumed British offensive forced the Germans back 3 kilometres (1.9 mi) and diverted reserves from the French and the French general offensive had less effect than the attack of 9 May, only gaining small amounts of ground despite the expenditure of twice as much artillery ammunition, at the cost of many casualties to both sides. Joffre ordered that the attack should only continue in areas where success had been achieved; on 18 June the main offensive was stopped and local attacks were ended on 25 June. The French attacks since 9 May, had advanced the front line about 3 kilometres (1.9 mi) towards Vimy Ridge, on a 8-kilometre (5.0 mi) front. The failure of the French attempt to break through, despite the expenditure of 2,155,862 shells and the loss of 102,500 casualties, led to recriminations against Joffre within the French army and the Chamber of Deputies; the German Sixth Army lost 73,072 casualties.