What Napoleon determined on was an operation far more decisive. He saw that that part of the Prussian army which lay in the neighborhood of Sombreffe, Tongrinelle and Balâtre, placed there, as it had been, for the purpose of protecting the communications with Namur, would in all probability not dare to move from its position, and would accordingly not be able to take any active part in the battle. He would therefore have to deal only with that portion of the enemy’s army which lay between Sombreffe and St. Amand,—say, two-thirds of their entire force. He also saw that if the enemy’s centre, between Ligny and Sombreffe, could be broken, the Prussian right wing would be separated from the rest of the army, and that he might hope to overwhelm it. He saw also one other thing. If, at or about the time when this success should be obtained, a strong column from Marshal Ney’s command could march down the Quatre Bras-Namur turnpike and move upon Brye, that success would almost certainly be of the most decisive character.[344] Attacked in front and rear at the same time, its connection with the rest of the army severed, surrounded by superior numbers, the utter rout of that part of the Prussian army was inevitable. (See Map 6.) At one o’clock the French army had arrived, and was in and about Fleurus. The Emperor threw the 4th Corps, Gérard’s, about 16,000 strong,[345] with 38 guns, far to the right, opposite the whole front of the village of Ligny; the 3d Corps, Vandamme’s, about 19,000 strong,[346] with 38 guns, connected with the left of the 4th Corps, and, assisted by Girard’s division of the 2d Corps, about 4,300 strong,[347] with 8 guns, menaced the Prussians in the village of St. Amand; while the cavalry of Pajol and Exelmans, to the number of about 6,500 men,[348] with 24 guns, supported by Hulot’s division of the 4th Corps, observed the Prussian left wing,—stationed from Sombreffe to Balâtre. The Guard, with Milhaud’s Cuirassiers, in all about 22,000 men, with 102 guns,[349] was kept in reserve, near Fleurus, ready to strike the final blow when the enemy in Ligny and St. Amand should have been sufficiently weakened by a continuous struggle of three or four hours. The whole force consisted of 67,787 men, of whom 13,394 were cavalry, with 210 guns.[350] These dispositions consumed perhaps an hour or more. At 2 o’clock the chief-of-staff, Soult, wrote[351] to Marshal Ney, informing him that, at half-past two Marshal Grouchy, with the 3d and 4th Corps, would commence an attack on a Prussian corps stationed between Sombreffe and Brye; that it was the Emperor’s intention that Ney should also attack the enemy before him; and, after having vigorously driven them, should fall back upon the main army to join in enveloping this Prussian corps, of which mention had just been made.