La Bassée
If the French Tenth Army captured Vimy Ridge and the north end of the Artois plateau, from Lens to La Bassée, as the First Army took Aubers Ridge from La Bassée to Lille, a further advance of would cut the roads and railways used by the Germans, to supply the troops in the Noyon Salient from Arras south to Rheims. The French part of the offensive was cancelled when the British were unable to relieve the French IX Corps north of Ypres, which had been intended to move south for the attack and the Tenth Army contribution was reduced to support from its heavy artillery.