During my stay at Compiègne all appreciations of the situation pointed to the immediate investment of Paris by the right wing of the German Army as being the enemy's first objective.
It is fairly certain that the concentration of an important new Army on the western flank of the British, to the north of Paris, was quite unknown to the Germans, and did not enter into their calculations until some days later.
We had also the best reason for believing that the German Higher Command regarded the British Forces as shattered and almost useless, at any rate so far as any effort which we could make for the defence of Paris was concerned. In fact, believing the capital to be practically at its mercy, the right wing of the German Army was blindly marching into a veritable hornet's nest, in spite of the backward condition of the Paris defence.
On the 29th a very brilliant and successful attack by the French 5th Army at Guise heavily defeated three German Army Corps and threw them back with severe loss. This had a great effect in assisting the retreat, for it not only enabled the 5th Army to hold its own for some time on the Oise, between Guise and La Fère, but it considerably relieved hostile pressure on the British and on the French troops on our left.
From Roye on the west, Montdidier, Noyon, La Fère, Guise, up to Hirson on the east, the heads of the Allied columns were established, well covered by their advanced cavalry.
Throughout this day reports often contradictory and conflicting reached me. It was quite clear that our position on the Oise was being dangerously threatened by superior forces, and I felt it to be impossible to stand on that line even until we could make good some of our heavy losses, and I could not hope to get anything up for several days to come.
With great reluctance I ordered the retreat to be continued to the line of the Aisne from Compiègne to Soissons, but in view of the knock given to the enemy at Guise by the 5th French Army, and the desire expressed by General Joffre that the Allied forces should hold their ground as long as possible and only retire when necessary, I directed commanders to carry out their marches with all deliberation, and to take advantage of every opportunity to check the enemy's advance.