As far as Napoleon was concerned, preparations got under way at the end of
August. Working at the Palace of St. Cloud, he pored over his maps (he had a
hand-painted, 1:100,000 set that covered the whole of Europe, a rare achievement
for those days). Within days, he had formed a preliminary plan for concentrating
theGrande Arme ́eat Bamberg. Berthier, who was not yet aware of the secret, was
asked to present a comprehensive report on the state of the army. Similar reports,
concerning munitions and supplies, were demanded of Dejean. Since the French
army had never taken this particular route when fighting in Germany, not much
information was available on towns, villages, rivers, fortresses, and the like.
Hence, officers of the statistical bureau were sent to visit the French embassies
at Leipzig and Berlin, travelling slowly to explore the roads that led through the
Frankenwald and Saxony towards Prussia further north. Indeed, as long as the
campaign lasted, Napoleon was constantly asking the marshals to present him
with any piece of topographical information that might prove useful to him.
On 10 September, Marshal Bessieres, who commanded the Imperial Guard,
was ordered to prepare his force for the field. 34 Precautionary orders also went
out for three other corps to be concentrated at Wu ̈rzburg as soon as the news of a
Prussian declaration of war arrived. On 18 September, the day when Napoleon
learnt that Prussia had declared war and invaded Saxony (the news had taken five
days to cover the 600 miles from Berlin to Paris), the iron dice were cast. Three
days later, informed by Berthier that the Prussians, moving faster than expected,
had crossed the Elbe and were marching south-west towards Hof and Hanover, he
departed for Mainz, on the river Rhine, which at that time marked the frontier
between France and Germany. Having taken leave of the empress there, on
2 October, he reached Wu ̈rzburg, the town he had designated as the westernmost
point of the front behind which theGrande Arme ́ewas to assemble. As he arrived,
Murat, having received news from his cavalry patrols operating in Saxony,
informed him that he had located the 150,000-strong Prussian army at Erfurt. 35
By this time, Napoleon had made up his mind as to the way he wanted the
campaign to develop. In a letter to his brother, King Louis of Holland, he explained:
It is my intention to concentrate all my forces on my extreme right, leaving all the country
between the Rhine and Bamberg completely uncovered in such a way as to have almost
200,000 men united in the battlefield. If the enemy [assumed to be moving slowly west from
Erfurt] sends detachments into the area between Mainz and Bamberg I shall not be bothered,
since my line of communications goes back to Forchheim, which is a little fortress close to
Wu ̈rzburg....[The enemy, who does not know this] believes my left to be on the Rhine and
my right on the Bohemian border, and that my line of operations is thus parallel to my front.
He may therefore try to attack my left, in which case I shall throw him into the Rhine. 36
He also took the opportunity to review theGrande Arme ́e, 180,000 men divided
into eight numbered corps, who were now well on their way to the pre-selected
starting positions.
On their side, the Prussians were equally clueless to what their enemy was
planning to do. To a large extent, this was because of the French cavalry patrols
which covered their army’s exposed northern flank, hiding its movements and
Napoleon and the Dawn of Operational Warfare 25