Reaching the zenith

This article is from Military History Matters issue 143

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The opening decade of the 19th century saw Napoleon at the height of his power, in control of an empire that stretched from the Channel coast to the borderlands of Russia. Only from 1809 did his ascendancy begin to decline. He was without question the dominant figure of his age, admired and reviled in equal measure by his contemporaries. Two centuries on, the debate continues about the reasons for Napoleon’s exceptional run of military victories. He had few rivals in his capacity for forward-planning, his intuitive grasp of the nature of the battlefield, and his ability to lead and motivate an army. A more critical view is that he lacked originality and was a hasty improviser who was lucky to encounter less able opponents.

Controlled aggression

Napoleon was an active practitioner with little time for military theory. His written statements on the nature of warfare are sparse and uninformative, going little beyond the need to exploit circumstances as they arise. ‘There are no precise or definite rules,’ he once declared. ‘The art of war is simple, everything is a matter of execution.’ At the heart of Napoleon’s thinking was a ruthless belief in offensive action. The aim was to engage and smash the main enemy force in a decisive battle. Sieges and prolonged occupations of cities or territory were distractions from the main purpose.

The classic illustration of this approach was the campaign that Napoleon undertook in the second half of 1805, when he set out from France to crush the forces of Habsburg Austria. The good roads of western and central Europe enabled the 176,000-strong Grande Armée to make rapid progress. In October, barely seven weeks after leaving the camp at Boulogne, it surrounded General Karl Mack’s 33,000-strong army at Ulm in southern Germany, leading to a practically bloodless capitulation. Five weeks later, after marching a further 500 miles to the east, the French defeated a combined Austro-Russian force at Austerlitz in the present-day Czech Republic. This was an even more remarkable victory, achieved in the depth of winter at the end of extended lines of communication.

At Austerlitz, widely regarded as Napoleon’s masterpiece, he induced Emperor Francis II and Tsar Alexander I to accept battle on his own terms. By withdrawing his troops from the Pratzen Heights, a plateau that dominated the battlefield, Napoleon created a false impression that he was ordering a retreat. In fact, it was a manoeuvre designed to lure his opponents on to ground that he had chosen. He deliberately overextended his right wing, encouraging the enemy to concentrate their attack there, only for the French to be reinforced by fresh troops arriving under the command of Marshal Louis-Nicolas Davout. Meanwhile, taking advantage of the mist that covered the low ground, two French divisions emerged to retake the heights, driving the allied forces off in confusion. The victory was complete when Napoleon ordered his artillery to fire on the enemy as they retreated across the adjoining frozen lakes, breaking the ice and sending many soldiers to a watery tomb. Together, Ulm and Austerlitz effectively gave France control of central Europe.

Critical to Napoleonic campaigning was an emphasis on rapid movement and the concentration of force. Important units were sometimes moved by wagon, as in 1809 when the French had to mobilise quickly to meet a revived Austrian threat. However, the wagons’ limited carrying capacity, and shortages of vehicles and horses, meant that forced marches were the usual mode of transport. ‘The emperor has discovered a new way of waging war,’ his soldiers famously observed, ‘he makes use of our legs instead of our bayonets.’ This was not, of course, the whole story. After closing with the enemy, French infantrymen were expected to hold their positions, often at great cost, while awaiting the arrival of the rest of the army.

The need for speed was dictated by the increased size of armies since the start of the French Revolution. The opposing sides at Austerlitz had upwards of 70,000 men each; four years later, at Wagram, more than 300,000 soldiers took part. Historian Jonathon Riley described Napoleonic armies as ‘moving cities’ which, like their civilian counterparts, consumed vast amounts of food, water, and medical care. The 18th- century agricultural revolution had led to major improvements in food-production. Even so, an army had to keep moving, as it would quickly strip an area of its natural resources if it stayed still for long. The problem was worsened by dependence on horsepower, with the daily food consumption of a horse being ten times that of a soldier.

Napoleon’s success rested on an intensely personal style of command. As we have already noted, he famously claimed that ‘one bad general is worth two good ones’. Combining the twin roles of supreme commander and head of state, he had no peers, only subordinates. The imperial headquarters evolved into a complex staff apparatus, but its role was essentially to implement the master’s will. Napoleon’s long-serving chief of staff, Marshal Louis-Alexandre Berthier, made himself indispensable by his ability to carry out instructions with immense attention to detail – a task that entailed deciphering the emperor’s notoriously difficult hand-writing. Berthier willingly recognised his subordinate status, telling Marshal Ney in 1807 that ‘the emperor needs neither advice nor plans of campaign. No one knows his thoughts and our duty is to obey.’