FRENCH OFFICIAL ACCOUNT
As early as September 11 the Commander in Chief had directed our left army to have as important forces as possible on the right bank of the Oise. On September 17 he made that instruction more precise by ordering "a mass to be constituted on the left wing of our disposition, capable of coping with the outflanking movement of the enemy." Everything led us to expect that flanking movement, for the Germans are lacking in invention. Indeed, their effort at that time tended to a renewal of their manoeuvre of August. In the parallel race the opponents were bound in the end to be stopped only by the sea; that is what happened about October 20.
Allies in the race to the sea.
The Germans had an advantage over us, which is obvious from a glance at the map—the concentric form of their front, which shortened the length of their transports. In spite of this initial inferiority we arrived in time.
From the middle of September to the last week in October fighting went on continually to the north of the Oise, but all the time we were fighting we were slipping northward. On the German side this movement brought into line more than eighteen new army corps (twelve active army corps, six reserve corps, four cavalry corps). On our side it ended in the constitution of three fresh armies on our left and in the transport into the same district of the British Army and the Belgian Army from Antwerp.
Resistance in Battle of Flanders.
For the conception and realization of this fresh and extended disposition the French command, in the first place, had to reduce to a minimum the needs for effectives of our armies to the east of the Oise, and afterwards to utilize to the utmost our means of transport. It succeeded in this, and when, at the end of October, the battle of Flanders opened, when the Germans, having completed the concentration of their forces, attempted with fierce energy to turn or to pierce our left, they flung themselves upon a resistance which inflicted upon them a complete defeat.
The movement began on our side only with the resources of the army which had held the left of our front during the battle of the Marne, reinforced on September 15 by one army corps.
This reinforcement, not being sufficient to hold the enemy's offensive (district of Vaudelincourt-Mouchy-Uaugy), a fresh army was transported more to the left, with the task "of acting against the German right wing in order to disengage its neighbor, * * * while preserving a flanking direction in its march in relation to the fresh units that the enemy might be able to put into line."
Reinforcements for the First Army.