This matter is an important one to settle, because some Prussian historians claim that Blücher gave battle at Ligny relying on Wellington’s agreement to support him. We cannot decide on this question at the present stage of our narrative; but we have already seen that Blücher gave orders for his four corps to concentrate at Sombreffe without any definite agreement or understanding with Wellington that he was to be assisted by the English in the battle that was almost certain to occur as a consequence of this concentration. All he had a right to expect was, that the Duke, as soon as he was informed of the situation, would at once assemble his forces, and, if he could safely and wisely do so, would march to the assistance of his ally.[144] But the Prussian Marshal took the risk of the English general’s not coming to his support in the next day’s battle; for, in the first place, he knew the scattered situation of the Anglo-Dutch troops, and that it would take a couple of days or so to get them together; and, secondly, he could not be sure that Napoleon might not, by operating with a part of his army by way of Mons and Hal, induce the Duke to concentrate his forces so far to the westward as to put it out of his power to render any help to an army that was fighting in front of Sombreffe. We have stated that, on the evening of the 14th, Blücher ordered the IId, IIId and IVth Corps to concentrate at or near Sombreffe. In compliance with these directions the IId and IIId Corps respectively concentrated, and marched rapidly towards Sombreffe. But Bülow, whose headquarters were at Liége, and who had, in obedience to his first orders, concentrated his corps, took it upon himself to disobey a subsequent order which he received about eleven o’clock in the morning of the 15th, directing him to march at once upon Hannut, and to put off the execution of this order until the next day. It is hardly worth while to undertake to decide how far Gneisenau, Blücher’s chief-of-staff, was, as has been often asserted, partly to blame for this mischance, by not inserting in the order a statement to the effect that hostilities were imminent. The matter has been often discussed;[145] it would seem that Bülow ought to bear the largest share of the blame; but why Gneisenau, upon whose shoulders lay the burden of effecting a concentration of the entire army by the morning of the 16th, should have omitted, when a battle was imminent, to put the commander of his most distant corps in possession of the facts of the situation and of Marshal Blücher’s intentions, it is certainly not easy to see. In such an exigency, the chief-of-staff must be held to the duty of omitting nothing that would tend to accomplish his task.