Joffre directed the operations first from Bar-sur-Aube and afterwards from Romilly.
As you see, the half-circle formed by the Allies, into which the Germans imprudently penetrated, was supported at the western extremity by the entrenched camp of Paris and at the eastern extremity by the fortified position of Verdun. The River Marne flows through the middle.
Although the battle was only to begin on the 6th, General Maunoury's Army was already engaged the day before. Its orders were to advance to the River Ourcq (see map), but, despite furious fighting, it was unable to get there.
The British forces were to occupy a line running north and south, with Coulommiers as point of support. Unfortunately, the exceedingly fatiguing retreat it had just accomplished, retarded the execution of the necessary volte-face. The map shows them on the 5th, still far to the south of Coulommiers.
The fact that neither of these two forces was able to take up its assigned position greatly increased the difficulties of the turning movement planned by Joffre.
In front of the forces under Maunoury and French, were the right and centre of the First German Army, under Von Kluck.
The Fifth French Army, under General Franchet d'Esperey, whose position extended from the north of Provins to Sézanne, delivered a frontal attack against the left wing of Von Kluck's army and the right wing of the Second German army under Von Bulow.
At the right of Franchet d'Esperey's army was the Ninth French Army under General Foch, whose task it was to cover his neighbour on the left by holding the issues south of the Marshes of St.-Gond.
Opposing Foch was the left of Von Bulow's army, with the right of the Third German Army commanded by Von Hausen.
The Fourth French Army, under General Langle de Cary, was minus two army corps which had helped to form Foch's army. This diminution of the forces of the Fourth Army prevented the latter from breaking off contact with the enemy. While, at the extreme left, General Maunoury had already begun his advance towards the River Ourcq, General Langle de Cary received orders to hold up the opposing forces under the Duke of Wurtemberg. Unfortunately, Langle de Cary's forces had not sufficient liberty of movement to effect the necessary volte-face.