The first battle of Artois, 27 September-10 October 1914, was part of the Race to the Sea, a series of encounter battles that set the line of the Western Front for most of the First World War. After static warfare developed on the Aisne, both Joffre and Falkenhayn began to search for troops they could use to turn the northern flank of the line, between the Aisne and the coast. Both found their armies in Lorraine. Joffre moved Castelnau’s Second Army to the area south of Amiens, Falkenhayn moved Crown Prince Rupprecht’s Sixth Army to St. Quentin.
The two armies first clashed in Picardy (22-26 September) and around Albert (25-29 September), without success. The search for an open flank moved further north, towards Arras. Two infantry and one cavalry corps from the French Second Army, under the command of General Maud’huy, were detached and sent north. Once at Arras they found a relatively open flank, populated at most by detachments of German cavalry, and began to advance north east, up the river Scarpe, towards Vimy. There was now a sizable gap between the northern and southern elements of the Second Army, protected by a force of French territorial troops.
On 28 September Falkenhayn ordered Prince Rupprecht to attack Arras. Rupprecht in his turn decided to attempt to outflank the French position at Arras, and on 3 October sent his reserve corps north of the city and the IV cavalry corps even further north towards Lille. He also pressed the line of territorials south of the city.
The German attack caused a crisis. By the end of 4 October Maud’huy was in serious danger of being cut off. He had lost contact with his cavalry to the north, and a gap had developed on his southern flank. He signalled to Joffre that he would have to retreat, and asked which direction to withdraw. Joffre was worried that if this happened, Castelnau would retreat south of the Somme, abandoning the valuable industrial areas of northern France.
Joffre responded by reorganising the northern armies. Maud’huy’s detachment was formed into a new Tenth Army. The Second and Tenth armies along with any other troops in the area were grouped together, and General Foch appointed to command them, as Joffre’s deputy. Finally, Castelnau was ordered to hold his ground.
Foch made a lightning tour of his new command. Over the next two days he visited the British, Belgians as well as Maud’huy and Castelnau. His energy reinvigorated the Allied defence around Arras, and by the end of 6 October the crisis was over. Falkenhayn turned his attention further north, to Flanders and the only possible open flank. There he would encounter the British at Ypres and the Belgians on the Yser, and the Race to the Sea would end in a draw.