Castelnau
on the left of Manoury's army, in the deployment of the army of
General de Maud'huy to the left of the army of Castelnau, in the
transference of the British army to the left of the army of Maud'huy,
in the relegation of the army of Urbal to the left of the British
army, the army of Urbal being later flanked by the Belgian army
which came out of Antwerp. In order to accomplish this new and
extended disposition of forces the French General Staff was compelled
to reduce to their extreme limits the effective strengths of the
armies of the east and of the Oise, and as a result to make the
maximum use of the means of transport. In this it succeeded. When
the great battle of Flanders was waged toward the end of October,
the Germans, trying to turn the French left and to pierce it, found
themselves facing considerable French forces, which, allied with the
British and Belgian armies, completely barred the passage against
them.

From the 15th of September, 1914, it was clear that the Germans
were making a great effort to try and overwhelm the French left.
General Joffre parried the attack, reenforcing at first the army
of Manoury by an army corps, then transferring to the left of the
army of Manoury the entire army of Castelnau that was in Lorraine.
A corps of cavalry and four territorial divisions commanded by
General Brugere received the order to establish itself on both banks
of the Somme and protect the detraining of the army of Castelnau.

From September 21 to September 26, 1914, all the French forces
that had newly arrived were engaged in the Lassigny-Roye-Peronne
region. They succeeded in withstanding, not without difficulty, the
German attack, but they could not advance. The Germans determinedly
and unweariedly continued to mass new forces on their right. On
the left of the army of Castelnau it was therefore necessary to
establish a new army. It was established on September 30, 1914,
under the command of General Maud'huy. From the first days of October
this army waged violent conflicts in the region of Arras and of
Lens. It found facing it two German cavalry corps, the Guard, four
active army corps, and two reserve corps.

General Joffre continued without intermission to send new forces
to the left. On October 4, 1914, he called on General Foch in the
north and charged him with the duty of coordinating the action of
all the armies in that region: those of De Castelnau, Maud'huy,
and the territorial division