At the beginning of the campaign, Napoleon, with the Grand Army, had taken his route through the Tyrol, ascending the rivers Inn and Isar, had defeated Archduke Charles at Eggmühl and driven him at Ratisbon, which he took by storm, across the Danube into the mountains of Bohemia; thus he had thrust himself between the Austrian army and the capital; then, having detached Davout with 40,000 men to hold the Austrian general in check, he had moved down the Danube and made himself master of Vienna; meanwhile, Napoleon’s generals Eugène Beauharnais and Macdonald, advancing victoriously from the Italian side through Dalmatia, Carniola, and up the valley of the Mur—in which Jellachich was severely beaten—pressed on to join their commander-in-chief. Meanwhile, Archduke Charles, who since his defeat at Eggmühl had been slowly moving on the north bank of the Danube downstream—hoping to find a favourable opportunity for a successful engagement and to save the empire right at the gates of the capital—took up a position with his army on the Bisamberg, opposite the island of Lobau and another small islet, which here divide the Danube into four branches.

The Archduke was at the head of 100,000 men and hourly expected to be joined by the 40,000 men of his brother, the Archduke John, which would have been increased to 60,000 if John, as he had been expressly ordered, had united with Kolowrat at Linz, thereby taking up a commanding position in the rear and on the main line of communication of Napoleon.

Napoleon had concentrated under his own supreme command 80,000 excellent, ready-for-action soldiers, including the Imperial Guard and the reserve cavalry of Bessières, and intended to cross the Danube and give battle to the Archduke Charles, hoping to destroy him before the arrival of his reinforcements. For this purpose he threw a very strong bridge, supported by 68 large boats and 9 enormous rafts, from the right bank to the island of Lobau, and a lighter bridge of pontoons from the island of Lobau to the Marchfeld, halfway between the villages of Aspern and Essling; and on the morning of the 21st of May he began with the utmost rapidity and care to move his troops across. The Austrian commander watched from his position on the hill this reckless manoeuvre, by which the Emperor was bringing his immense army across a broad and rapid river by means of a single bridge, which could only permit a slow and gradual defile of the soldiers of all arms over its long and narrow passage—difficult for the cavalry, still more difficult for the artillery—and which, should he be forced to retreat, offered scarcely any means of bringing the army to safety. When the Archduke Charles perceived this, he resolved instantly to seize the opportunity to destroy the half of the French army on the north bank, while the other part was still crossing the bridge or on the south bank. He ordered Kolowrat, Nordmann, and the other commanding officers who were stationed higher up the river to have boats with heavy materials and combustibles in readiness to destroy the bridges at the proper moment, and meanwhile kept his great army out of sight; to his cavalry and the outposts he gave orders to offer only a feigned resistance and then to fall back before the advancing French, who were commanded by Masséna. At 12 o’clock, when more than 40,000 Frenchmen were already on the north bank, the enemy’s manoeuvre had advanced sufficiently far for the Archduke Charles to seize the initiative.

At this moment he threw himself with 80,000 men, including 14,000 excellent cavalry, and 288 guns from the wooded heights of the Bisamberg upon the enemy, making the two villages of Aspern and Essling, in Napoleon’s flanks, the main points of his attack; the central space between these two strong places, consisting mostly of stone buildings and surrounded by garden walls and many enclosures, was occupied by powerful Austrian batteries, covered mainly by cavalry and, in the rear, by Hohenzollern’s infantry reserve. The fighting during the two flank attacks was fearful, the fury of the assaults and the stubbornness of the defence almost without parallel in the history of war. Both villages changed hands several times, and the Austrian artillery raged so terribly in the French lines that Napoleon ordered a great cavalry charge to capture the batteries if possible. The superb French Guard cuirassiers attacked with their customary impetuous bravery, routed the Austrian horse, and would have taken the guns; but these were rapidly withdrawn, and the infantry formed squares, which, as later at Waterloo, resisted all attempts to break their solid formation, finally repulsed the cavalry, and forced them, broken and decimated, to retire to their own lines. Meanwhile, Aspern was taken by the Austrians; their centre gained ground slowly but irresistibly, despite the heroism of the cuirassiers, who charged again and again with constantly diminished numbers and alone preserved the French lines from an enemy breakthrough.

The night brought a brief interruption of the struggle; but the French had suffered a clear defeat in a decisive battle; their left flank had been turned, their centre pushed back almost to the bridges; and although Essling on their right wing had been held by the bravery of Lannes, it was surrounded by the Austrians, who slept on their arms among the dead Frenchmen and only waited for daybreak to renew the attack.

Throughout the night, however, fresh troops moved across the bridges and streamed onto the Marchfeld, and at daybreak Napoleon, after all the losses of the previous day, had a full 70,000 men on the battlefield, while Davout, at the head of another 30,000 men, began to cross. The battle commenced with renewed attacks on the two contested villages; Essling was taken by the Austrians and Aspern retaken by the French. Both places were the scene of desperate, day-long fighting, and both changed hands several times in hand-to-hand combat, but finally remained in the hands of the Austrians, who towards evening pushed their artillery forward beyond both villages and brought their cross-fire effectively to bear on the rear of the French. But during these bloody combats, Napoleon, relieved by large reinforcements of the necessity of acting on the defensive, had resorted to his favourite manoeuvre, an overwhelming attack on the centre. At the head of an immense column of over 20,000 infantry, preceded by 200 guns and followed by powerful masses of cavalry, he ordered Lannes and Oudinot to attack the Austrian centre directly, where the lines appeared weakest, between the left wing of Hohenzollern and the right of Rosenberg. At first this heavy attack seemed completely successful; the Austrian lines were broken, and a huge gap was torn between Hohenzollern and Rosenberg, into which the cavalry rushed with terrifying impetuosity and cut their way clean through to the reserves of Prince Reuss stationed far in the rear. Already the cry spread that the battle was lost; but Archduke Charles proved equal to the difficult situation; the grenadiers of the reserve were brought up at the double and formed into squares chequerwise; the numerous dragoons of Prince Liechtenstein galloped up, and with the flag of Zach’s regiment in his hand, the brave prince renewed the fight.

The immense column under Lannes could advance no further; it was brought to a halt and began a fire-fight with the squares; unable to deploy, it was shot to pieces by the concentrated fire of the batteries at half musket-range. In vain the cavalry stormed against the bayonets of the squares; not one wavered or was broken, until at last the Austrian dragoons of the reserve burst forth with loud shouts, and in their turn attacked the French cuirassiers, scattered them, drove them back in disorder upon their infantry, and completed the confusion. Immediately after this reverse, Hohenzollern, with six Hungarian grenadier regiments, broke through the French lines on the right of the centre and drove everything before him as far as the rear of Essling, which, together with Aspern, was finally captured by the Austrians. While the Austrian centre now drove the French army, though with unprecedented exertions, in full retreat to the island of Lobau, the Austrian batteries from these villages brought a destructive cross-fire to bear upon the bridges, every shot telling with devastating effect upon the crowded masses of men and horses.

To render the perilous situation of the French still worse, the bridge connecting the island of Lobau with the southern bank was meanwhile destroyed by Austrian fire-ships and rafts, making it for the moment impossible for the French to escape from the island. Meanwhile the unparalleled steadiness of the French rearguard kept the Austrians in check, until towards midnight, after the last of the enemy had withdrawn from the battlefield to the island, the thunder of the Austrian batteries fell silent, and the exhausted artillerymen, completely worn out by the exertions of that unparalleled and glorious day, fell asleep beside their guns.

Seven thousand Frenchmen were buried by the victors on the battlefield; 29,793 were brought to Vienna as wounded or prisoners. Lannes and Saint-Hilaire were mortally wounded and died a few days later. On the Austrian side, 87 superior officers and 4,200 soldiers had fallen, besides 16,300 wounded. But the victory, won right before the gates and almost within sight of the capital, was complete; the enemy, broken, defeated, and disheartened, was penned up on the little island of Lobau, and had the Archduke John, in accordance with the order given him, appeared on the morning after the defeat of Aspern in the rear of the French with 60,000 fresh troops, the result would not have been difficult to foresee.

But Napoleon’s hour had not yet come, and the peoples were to suffer four more years before the final overthrow of the warlike Colossus on the battlefields of Leipzig and Waterloo was to restore to them their lost liberty.