In the justifiable belief that Ney was duly carrying out his orders Napoleon at half-past one opened the battle of Ligny. He had expected to have to deal with but a single Prussian corps, but the actual fact was that, while he had 74,000 men on the field, Blücher had 87,000 with a superior strength of artillery. The fighting was long and severe. From the first, recognising the defects of his adversary's position, Napoleon was satisfied that he could defeat the Prussian army. But he needed to do more--to crush, to rout it, so that he need give himself no further concern regarding it. This he saw his way to accomplish if Ney were to strike in presently on the Prussian right; and so, with intent to stir that chief to vigorous enterprise, the message was sent him that "the fate of France was in his hands." The battle proceeded, Blücher throwing in his reserves freely, Napoleon chary of his and playing the waiting game pending Ney's expected co-operation. About half-past five he was preparing to put in the Guard and strike the decisive blow, when information reached him from his right that a column, presumably hostile, was visible some two miles distant marching toward Fleurus. Napoleon sent an aide to ascertain the facts and until his return postponed the decisive moment. Two hours later the information was brought back that the approaching column was D'Erlon's from Ney's wing. This intelligence dispelled all anxiety. Strangely enough, no instructions were sent to the approaching reinforcement, and the suspended stroke was promptly dealt. The Prussians, after desperate fighting, were everywhere driven back. Napoleon with part of the Imperial Guard broke Blücher's centre, and the French army deployed on the heights beyond the stream. In a word, Napoleon had defeated the Prussians, but had neither crushed nor routed them. There was no pursuit. D'Erlon's corps on this afternoon had achieved the doubly sinister distinction of having prevented Ney from gaining a probable victory at Quatre Bras, and of detracting from the thoroughness of Napoleon's actual victory at Ligny. While it was leisurely marching towards Frasnes in support of Ney, it was diverted eastward towards the Prussian right flank in consequence of an order given (whether authorised or not is uncertain) by an aide-de-camp of the Emperor. It was about to deploy for action, when, on receiving from Ney a peremptory order to rejoin his command; and in absence of a command from Napoleon to strike the Prussian flank, it went about and tramped back towards Frasnes. D'Erlon's promenade was as futile as the famous march of the King of France up the hill and then down again.