On the evening of July 4, 1809, Emperor Napoleon’s Grande Armee prepared to cross a narrow waterway from Lobau Island to Marchfelt, a large, flat plain that bordered the eastern banks of the sinuous Danube River. Marshal Nicolas Oudinot’s II Corps was among the first to attempt a passage, boarding boats with a minimum of delay and little or no confusion. No fewer than 6,000 grenadiers and voltigeurs had embarked, the men wearing white armbands to help identify French advance units and lessen the chance of friendly fire casualties.
Such identification was needed because, as the evening progressed, a storm developed that was both unseasonable and intense. French troops were lashed by a heavy downpour, a deluge of almost Biblical proportions accompanied by howling winds. French batteries on Lobau had opened a steady fire, their thunderous reports matched, and even surpassed, by peals of lightning.
French surgeon Dominique Jean Larrey, a veteran campaigner, recalled that troops were also pelted by hail, and “so intense was the darkness that we could only get our bearings during the flashes of lighting.” Some of the visibility problems were solved when French shells set the village of Gross Enzerdorf on fire. Flames engulfed the houses, the orange-yellow tendrils leaping so high into the air boatmen could get their bearings.
Once a foothold was firmly established on the eastern bank, French sappers went to work, rapidly putting preassembled bridges across the water. Once the spans were in place, the bulk of the Grande Armee began to cross. In spite of the weather and sporadic Austrian artillery fire, the whole operation went like clockwork. Shortly after 2 am, Marshal Nicholas Davout’s III Corps began crossing its assigned bridges without incident. His force included four infantry divisions and three cavalry divisions, altogether more than 30,000 men, yet all seemed to have made it safely across.
Somewhere in the pitch black awaited Archduke Charles von Hapsburg’s Austrian army, a force numbering 113,800 infantry, 14,600 cavalry, and 414 guns. Six weeks earlier Archduke Charles had pulled off something of a miracle when he defeated Napoleon at nearby Aspern-Essling. But the French emperor had not been decisively defeated and was now attempting to regain the initiative.
Knowing the fate of his empire was at stake, Napoleon supervised every detail of the operation. When Marshal Andre Massena’s IV Corps was about to cross, the squat emperor surprised the hard-working sappers by showing up at the bridgehead in person. A preassembled bridge was about to be swung across the channel. There were no fewer than 17 pontoons in the bridge, engineered to span a 178-yard gap. The idea was to swing the bridge across in one piece, a tricky and dangerous maneuver.
Napoleon, dressed as usual in his greatcoat and famed cocked hat, strode over to the officer in charge, a Captain Heckmann. His manner was brusk and to the point: “How long do you require for the swinging?” “A quarter of an hour, sire,” replied Heckmann. The emperor was not buying it. “I give you five minutes,” he snapped. Napoleon then turned to Henri-Gatien Bertrand, who was an engineering officer as well as an aide. “Bertrand, your watch!” he demanded.
The pontoon bridge managed to move flawlessly and all in one piece. It took eight minutes, but Napoleon was pleased enough to forgive the extra time. Still, there was not a moment to lose. Massena’s men began crossing at once, their boots sounding a rhythmic thud on the rough wooden planks. The marshal himself rode in a calash drawn by four horses from his own stables. His legs had been injured in a riding accident, so he could not walk or ride on horseback. Massena’s personal driver insisted on taking the reins, even though the carriage would be a perfect target for Austrian guns
By 10 am it was done: Napoleon’s army of 130,800 infantry, 23,300 cavalry, and 544 guns was safely across the Danube and poised for battle. There had already been some fighting that morning, savage and bloody, but still just a prologue of the main event to come. Who would prevail? The answer would determine the fate of Europe for some time to come.
The battle had its roots in the turbulent power politics of the period. Napoleon’s unrivaled genius on the battlefield led to peace treaties that too often humbled and humiliated his foes. Napoleon badly defeated Austria, once dominant in central Europe, in 1805 at Austerlitz. Afterward, Austria’s power was diminished and its reputation tarnished by a man who they considered an upstart at best. Filled with a burning desire for revenge, the Austrians bided their time, waiting for an opportunity to renew the contest.
The opportunity came early in 1809. Napoleon was in Spain, wrapping up a major campaign, and the French were taken completely by surprise. Archduke Charles was a competent if not overly imaginative general, and his first moves were good enough in this game of sanguinary chess. But check is not checkmate, and once Napoleon arrived on the scene the archduke was forced on the defensive.
For a time it looked like Napoleon was about to score another triumph. Vienna was captured, an important psychological blow, but victory would not be achieved until the Austrian army was vanquished. Archduke Charles wisely based his army north of the Danube, thus placing the great river between him and the Grande Armee. To attack the Austrians Napoleon would first have to cross the mighty river, no mean feat if his passage was contested. And once across, he might find himself fighting a major battle with the Danube at his back.
Napoleon responded to the problem with his usual thoroughness, at least it seemed so at the time. But by 1809 the emperor’s characteristic brilliance was being tainted by an all too human arrogance. He had come to believe in his own invincibility, and that, coupled with contempt for his foes, was to have near fatal results.
On May 20 Napoleon took a gamble. The French army crossed the river at Lobau Island, some four miles below Vienna, without adequate reconnaissance as to the enemy’s whereabouts. Worse still, the crossing depended on a single pontoon bridge that stretched a vulnerable 825 yards. The French managed to establish a bridgehead, but a vigorous attack by Archduke Charles on May 21 placed the whole Gallic operation in jeopardy.
The resulting fight is commemorated as the Battle of Aspern-Essling. It was a savage, two-day affair, and the French were hard pressed from the very beginning. Napoleon usually had the upper hand in battle, but this time the shoe was on the other foot. The French found themselves outgunned and outnumbered two to one, with reinforcements and ammunition conveyed over that single rickety bridge. The flimsy span was broken at least five times during the course of the battle, either by the Danube’s strong current or by Austrian fireboats.
The Lobau pontoon bridge was the French army’s lifeline, and when the bridge’s fragile beams parted, the French army was marooned. Finally accepting the inevitable, Napoleon ordered a general retreat to Lobau on the afternoon of May 22. It took time for such an amazing event to sink in. Although hard to fathom, Napoleon had been defeated in person.
The emperor himself was in something like a state of shock. For a good three days he was listless. His mind was seemingly paralyzed by the unaccustomed defeat. His mood was also darkened by the death of Jean Lannes, one of his best marshals and a close personal friend. But Napoleon’s energy and resolve soon returned, and he began planning for a comeback.
Napoleon knew that the French empire rested on shaky foundations, his continuing victories binding it together. If he sustained enough defeats, the whole grand empire would collapse like a house of cards. Russia, a nominal French ally, was more interested in nibbling away at Austrian territory than offering substantial help. And Prussia, dismembered and still smarting from its own defeat in 1806, also had to be watched.
But the emperor also had to contend with growing German nationalism. Austria and Prussia apart, the other German-speaking lands were growing restive under French domination. Napoleon’s Continental System, the economic blockade of Great Britain, was resented and brought hardships to German businessmen. Germany, formerly a patchwork quilt of approximately 300 petty states, had been consolidated into around 35 principalities, a French-driven process that ironically accelerated a pan-German feeling.
In spite of Napoleonic reforms, the Germans resented French rule, the presence of French troops, and French demands that they participate as allies in the emperor’s endless wars. They were restive, impatiently waiting for obvious signs of decline and defeat before rising up against the French occupiers. Napoleon had stumbled, but not fallen, that is, at least not yet. That is the reason the outcome of the next battle was of such vital importance. Napoleon had to win or risk losing everything.
As a first step the emperor temporarily withdrew all French troops from Lobau except Massena’s IV Corps. The island was then transformed into an entrenched camp, with strong fortifications bristling with at least 129 guns. More bridges were built, sturdy and strong, that linked Lobau to the mainland, but Napoleon realized the spans were in danger from fireboats or anything else the Austrians might place in the river to damage them. Taking no chances, the French drove poles into the riverbed upstream to catch any floating obstructions dumped into the Danube. Additionally, the Marines of the Guard manned 20 boats, an impromptu Danube River patrol to keep a watchful eye on things.