Davout swiftly organised the production and supply of equipment for the rapidly expanding army. Mills and factories turned out thousands of uniforms and tens of thousands of cartridges. New cannon were cast and pinioned to freshly constructed gun carriages. Horses were requisitioned across the country. All the while a steady flow of soldiers marched north towards the Sambre river where they camped across a wide front, waiting for the order to concentrate. Napoleon remained in Paris for as long as possible. He had sent a private message to the Emperor of Austria, begging for the return of his son and his wife. But there was no reply and his heart hardened towards the Austrians, and he vowed that he would avenge this cruel silence.

As he made a show of dealing with his civil obligations, all the time Napoleon’s mind was focused on planning the coming campaign, selecting his officers carefully. Murat’s request to serve under him was brusquely declined. Murat had foolishly declared war on Austria as soon as he heard of Napoleon’s escape from Elba and was defeated shortly thereafter and forced to flee to France. After his earlier treachery Napoleon could not trust him.

His uncertain hold on power meant that he must leave Davout to control Paris in his absence. Berthier would have been his first choice as chief of staff of the new Army of the North, but early in June came news that Berthier was dead. He had fallen from a window of his home in Bamberg, but it was not clear if it was an accident or something more sinister. In his place Napoleon appointed Soult, despite Soult’s protest that he lacked the ability to run the Emperor’s general staff, and was better employed on the battlefield.

On 7 June Napoleon ordered that the frontier with Belgium be closed. As a further security measure no mail or civilian traffic was allowed on to the roads, while the soldiers of the Army of the North began to concentrate on Philippeville less than a day’s march from the border. A week later Napoleon’s carriage and cavalry escort trundled into the small town of Beaumont where the headquarters for the army had been established. The usually quiet streets of the town were filled with soldiers and they jumped to their feet and cheered the instant they were aware that their Emperor had joined them. Napoleon, though exhausted by the preparations for the campaign, forced a smile and waved to them. Even amid the wild celebration his mind was coolly assessing their morale and he was pleased to see that there was no hint of the dull mood of resignation that had characterised the soldiers he had led a year ago. They pressed round the carriage, following it through the streets until it turned into the coachyard of the inn where Soult and his staff were waiting.