The issue of the battle of Waterloo, in fact, might have been entirely changed if the movements of troops not under the control of either of the commanding generals had been other than they were; it is this fact among others which gives the battle a peculiar interest. The position to the south of the villages of Mont St. Jean and Waterloo, known as the field of Waterloo, had been, some time before the campaign opened, reconnoitred by the English engineers; “the several sketches of the officers had been put together, and one fair copy made for the Prince of Orange; a second had been commenced for the Duke.”[688] The chief-of-engineers, Lieutenant-Colonel Smyth, who was present at the action of Quatre Bras, sent back to Brussels during the afternoon, presumably by the Duke’s direction, for a plan of this position; and the original sketches, which, together, constituted a plan, were forwarded to him by Captain Oldfield, the brigade-major of engineers.[689] The next morning, “upon the receipt of a communication from Blücher,”[690] the Duke obtained from Colonel Smyth these sketches, and gave them to Sir William De Lancey, his Deputy-Quartermaster-General, or chief-of-staff, “with orders” (as Major Oldfield states)[691] “to take up the ground on which we fought the next day. Colonel Smyth was at the same time desired to take the necessary measures for entrenching the village of Braine-la-Leud.” To this position, then, well understood and mapped out, the Duke of Wellington fell back on the afternoon of the 17th from Quatre Bras with that part of his army which was under his immediate command, and to it also he directed the greater part of the troops which were at Nivelles and other places. (See Map 13.)