The Battle of the Marne by G.H. Perris — Read

To understand how this withdrawal, so big with results, was possible, and to do justice to Sir John French's command in regard to it, we must leave Lamaze and Vautier at grips with the two German corps on the Ourcq, and turn for a moment to the situation south of the Marne.

On September 3, the British Army lay just south of Meaux, from Lagny to Signy Signets, having destroyed the Marne bridges behind it at General Joffre's request. Kluck, as we have seen, was then approaching the river from the north-west, coming on at a great pace. Several of his Staff officers, pelting eastward from Meaux in an armoured automobile at nightfall, did not see that the last arch of the Trilport bridge was broken, pitched over, and were drowned. A little study of the map will show that Kluck's rapid movement -- his pontoon corps established bridges of boats across the Marne on the night of the 3rd, and the next day his patrols were beyond the Petit Morin and on the Grand Morin -- required not simply a farther retreat, but a different direction of retreat, of the British force. To throw it up against the neighbouring French columns, those of the 5th Army (commanded by General Franchet d'Espérey since the evening of September 3) was exactly what Kluck was aiming at.