The Duke of Wellington spent the night after the battle of Quatre Bras at Genappe, but returned to the front “at daybreak, or soon after.”[535] A detachment of cavalry was soon afterwards sent out, which ascertained that the Prussians had been beaten the day before, and were now retreating on Wavre. This information reached Wellington about 7.30 A.M.[536] Blücher had sent an officer, Major Winterfeldt, from the field of battle the evening before to inform General Müffling of his intended retreat, but he had been wounded,[537] and the information had not reached the Duke. At 9 o’clock another officer arrived from Blücher,[538] Lieutenant Massow.[539] The Duke told him that he would fall back to the position of Mont St. Jean where he would give battle, if he were supported by one Prussian corps. This answer Massow carried to Blücher. He arrived at Wavre at noon. At this hour, as we are told by the latest Prussian historian,[540] it was not known where the IIId or IVth Corps was, and the reserve ammunition had not arrived.[541] No decided assurance could, therefore, be given during the day. Finally, about 11.30 P.M., news arrived from Bülow of the arrival of his corps at Dion-le-Mont, and about the same time a despatch from Müffling arrived, stating that the Anglo-Dutch army had taken position for battle at Mont St. Jean. Then Grolmann wrote to Müffling Blücher’s answer. It was sent off about midnight of the 17th. This despatch stated that Bülow would move at break of day by way of St. Lambert to attack the right flank of the enemy, and that the IId Corps would support the IVth Corps in this operation. The Ist and IIId Corps were to hold themselves in readiness to do the like. This despatch, which could not have reached Wellington until the morning of the battle of Waterloo, seems actually to have contained the first definite promise of support from Blücher.[542] Long before its arrival the Duke had taken up his position at Waterloo in the hope—in fact, in the expectation,—of receiving some such promise of assistance and support. Messages were doubtless exchanged, as we are told,[543] between the English and Prussian headquarters during the whole day. But the Duke received no positive assurance until the early morning of the 18th that the Prussian army, or any part of it, would come to his assistance. It is true that he was aware that the Prussians were concentrating at Wavre; and he knew that their object in so doing could be nothing else than to tender him their support in the battle that was sure to occur the next day. But it must have required all the resolution and courage which he possessed to have decided him to take up position for battle without having received any definite assurance that the necessary support would be furnished.