The French, as already noticed, had, about three o'clock, obtained possession of the Bois de Bossu and driven out the Belgians. They were in return themselves expelled by the British guards, who successfully resisted every attempt made by the French to penetrate into the wood during the day. As the English reinforcements arrived in succession, Maréchal Ney became desirous of an addition of numbers, and sent to procure the assistance of D'Erlon's division, posted, as has been said, near Marchiennes. But these troops had been previously ordered to succour Buonaparte's own army. As the affair of Ligny was, however, over before they arrived, the division was again sent back towards Frasnes to assist Ney; but his battle was also by this time over, and thus D'Erlon's troops marched from one flank to the other, without firing a musket in the course of the day. The battle of Quatre-bras terminated with the light. The British retained possession of the field, which they had maintained with so much obstinacy, because the Duke of Wellington conceived that Blucher would be able to make his ground good at Ligny, and was consequently desirous that the armies should retain the line of communication which they had occupied in the morning. But the Prussians, evacuating all the villages which they held in the neighbourhood of Ligny, had concentrated their forces to retreat upon the river Dyle, in the vicinity of Wavre. By this retrograde movement, they were placed about six leagues to the rear of their former position, and had united themselves to Bulow's division, which had not been engaged in the affair at Ligny. Blucher had effected this retreat, not only without pursuit by the French, but without their knowing for some time in what direction he had gone.