The Armée du Nord was deployed thusly around June 1st, 1815. The majority of the forces were already in, or not more than 1 to 2 days from the eventual theater of operations. The Guard was largely in Paris, and IV Corps was on the Moselle. Outside a division of VI Corps and cavalry divisions, these were troops that had any significant movements for the upcoming campaign.
The plan was brilliant to be sure, but the concentration maneuvers were extremely simple. It would be almost two weeks until most troops would march - Napoleon probably couldn't imagine that there would be any difficulties...
On June 1st, Soult proudly announced his love for Napoleon in the order of the day. On this same day, the Acte additionnel au constitutions de l'Empire was voted on, and rejected by Bourmont and his staff. Clouet, his chief of staff, claims to have talked Bourmont out of leaving the army right then; but Bourmont was determined to join the King as soon as possible! Yet this did not happen, for what good would it do to join the King without actionable intelligence, and in the process leave his division under a better (by being loyal) command? The actions of Bourmont and his staff never matched their actions of 1815 - and while their contemporaries never bought their story, an amazing number of historians have...
On June 2nd, Karl Friedrich Heinrich von der Goltz, a Prussian general serving as ambassador to Louis XVIII, wrote to the Prussian Chancellor Prince Hardenberg with the military details Guizot had just delivered, “… who got them directly by an employee in the office of Marshal Davout.” Guizot would later play a large role in the governments of Louis-Philippe alongside Soult, but always denied having been a traitor. The correspondence that proved his acts was not published until after his death... to this day, the extent of Royalist activities is largely unknown. They kept their secrets.
On June 3rd Napoleon asked Soult for the initial plan for concentration of the army on the Belgium frontier targeting a completion date of June
13th. The order began:
Give me a plan of movement for the Corps of Général Gérard or Corps of the Moselle, concealing it as much as possible from the enemy, because this corps is to march on Philippeville. It should arrive there on the 12th, marching as quickly as possible. Inform me about who will then command at Metz and Nancy. You will give the order at once to suspend the communications, and all of the posts, Thionville, Longwy, Metz, etc. must be strengthened.
June 14, the anniversary of Marengo, was Napoleon’s target date for the commencement of the campaign.
Also on June 3rd, Napoleon gave Drouot detailed instructions for the Guard's march from Paris to the Belgium Frontier - this began on June 5th.
On June 5th, Soult sent an order to Gérard to have the Armée de la Moselle march to Rocroi and to arrive by June 13th in seven stages. The Army of
the Moselle was comprised of IV Corps and was headquartered at Metz with divisions at Fontoy and Thionville. As we saw on June 3rd, Napoleon had asked Soult for a plan to deliver IV Corps to Philippeville by June 12th marching as quickly as possible. Instead, Soult’s order directed IV Corps to Rocroi which was a day’s march south of Philipeville, and worse, to arrive a day later than Napoleon’s original order. Had Soult and Napoleon discussed this change, presumably after having reviewed a plan Soult may have presented? Or was Soult operating on his own?
On June 7th Gérard received Soult’s order to concentrate on the Belgium frontier joining the Armée du Nord. Lettow-Vorbeck describes it thusly where 3 German miles was roughly equivalent to 7.5 kilometers:
The work the Emperor had assigned to the chief of staff was a tremendous one, and one can hardly blame the latter that only on June 5th, he issued the order to the 4th corps to start marching on the 7th and to reach Rocroi on the 13th, in seven stages of 3 miles each, via Stenay, Mézières. The commander of the corps, General Gérard, nevertheless was to remain in Metz until the 10th, in order to give the necessary instructions concerning the surveillance of the border between Metz and Thionville to General Rouyer who was to march out of Nancy on the 7th, with the 2nd division of the national guard. Probably Soult had used the term of “relieve” (relever), such as in the simultaneous notification to Vandamme, and this would explain why, on the 7th, Gérard had only one of his divisions march off, and had the other two follow on the 8th and the 9th. The cavalry and artillery of the corps were also assigned to the last squadron.
Interestingly, Lettow-Vorbeck saw this order around the turn of the 20th Century - it has since disappeared from the archives.
Whatever the text of this order said, the first significant error of the campaign was made. Though Napoleon intended IV Corps to execute a speedy march in order to be concentrated on the frontier by June 13th, the timetable Gérard executed meant IV Corps would be fully assembled at Rocroi on June 15th... more than a day later and half-day's march further south than Napoleon had originally ordered.
On June 9th, the march of IV Corps to the Belgium frontier was well under way. The 14th Infantry division, commanded by Bourmont, ended the day at Sivry-sur-Meuse; the 12th division bivouacked at Etain; the 13th division stopped at Conflans. Bourmont had covered about 29 kilometers.