It was the intention of Napoleon during his operations on this day to effect a separation between the English and Prussian armies, in which he had nearly succeeded.  Napoleon’s plan for this purpose, and the execution of it by his army, were alike admirable, but it is hardly probable that the Allied generals were taken by surprise, as it was the only likely course which Napoleon could have taken.  His line of operation was on the direct road to Brussels, and there were no fortified works to impede his progress, while from the nature of the country his numerous and excellent cavalry could be employed with great effect.

In the French accounts Marshal Ney was much blamed for not occupying Quatre Bras with the whole of his force on the evening of the 16th.  “Ney might probably have driven back the Nassau troops at Quatre Bras, and occupied that important position, but hearing a heavy cannonade on his right flank, where General Zieten had taken up his position, he thought it necessary to halt and detach a division in the direction of Fleurus.  He was severely censured by Napoleon for not having literally followed his orders and pushed on to Quatre Bras.”  This accusation forms a curious contrast with that made against Grouchy, upon whom Napoleon threw the blame of the defeat at Waterloo, because he strictly fulfilled his orders, by pressing the Prussians at Wavre, unheeding the cannonade on his left, which might have led him to conjecture that the more important contest between the Emperor and Wellington was at that moment raging.

It was at six o’clock in the evening of the 16th that the Drake of Wellington received the first information of the advance of the French army; but it was not, however, until ten o’clock that positive news reached him that the French army had moved upon the line of the Sambre.  This information induced him to push forward reinforcements on Quatre Bras, at which place he himself arrived at an early hour on the 16th, and immediately proceeded to Bry, to devise measures with Marshal Blucher in order to combine their efforts.  From the movement of considerable masses of the French in front of the Prussians it was evident that their first grand attack would be directed against them.  That this was Napoleon’s object on the 16th maybe seen by his orders to Ney and Grouchy to turn the right of the Prussians, and drive the British from their position at Quatre Bras, and then to march down the chaussee upon Bry in order effectually to separate the two armies.  Ney was accordingly detached for this purpose with 43,000 men.  In the event of the success of Marshal Ney he would have been enabled to detach a portion of his forces for the purpose of making a flank attack upon the Prussians in the rear of St. Amend, whilst Napoleon in person was directing his main efforts against that village the strongest in the Prussian position.  Ney’s reserve was at Frasnes, disposable either for the purpose of supporting the attack on Quatre Bras or that at St. Amand; and in case of Ney’s complete success to turn the Prussian right flank by marching on Bry.