The decision was a grave one, and was in some sense a departure from previous practice.
The enemy was now on the alert, the troops to be employed had already been severely tried in the earlier fighting of the year, and failure would have called down severe criticism upon the wisdom of abandoning so quickly the scene of our first great success.
"It was only after the first days of heavy fighting (in the battle of Bapaume), during which progress was comparatively slow and the situation full of anxiety, that the event proved that the step had been wisely taken.
"Then, when the success of this bold manoeuvre had declared itself, and the enemy had begun the first stages of his great retreat, the next critical period arrived on the 2nd September, when the powerful defences of the Drocourt-Queant line were attacked and broken.

The effect of this success was to render the whole of the enemy's positions to the south untenable and to throw him back definitely upon the Hindenburg line.
"Undoubtedly the most critical and anxious period of the whole advance arrived at the end of September.

The culminating attacks of the 27th and 29th of that month on the Canal du Nord and Hindenburg line defences shattered the most formidable series of field defences that military science has yet devised and drove the enemy into open country.

These attacks, indeed, accomplished far more than this.

They definitely broke the power of resistance of the German Armies in the field.