On May 9th, Napoleon drove back a tentative attack by Austrian 2nd Provisional Korps at St Polten. On the 10th, the forefront of the army pressed forward to Purkersoors, seeking to continue the impetus against the Austrian capital. After 40 days of campaigning, the French army is much reduced and the army that marches out to meet them at Purkersoors is fresh and well-equipped. It is the army that Charles has rapidly assembled after the surrender at Steyr. Unfortunately for the Austrians, their haste in mustering this army has required that the force be predominantly conscripts.

    It is a Landwehr Corps that strikes at Rossatz on the same day but Massena will be there with V Corps (and at Krems) so the Austrian conscripts are thrown back with heavy losses.

The battle at Purkersoors though shapes up to be a critical contest. Napoleon has proposed a peace treaty with the Coalition and he requires a decisive victory here if he hopes for an end to the war. Anything else would give too much hope to the coalition forces and the war would be extended. Napoleon is keenly aware of how exhausted his army is and imagines a disaster if he were to lose this battle with such extended lines of supply behind him.

For the Austrians, Archduke Charles knows that this may be a last desperate opportunity to halt the French and to gain a victory that would mean so much for coalition morale. It is true that the Austrian army is still trying to assemble more forces near the capital but the politics of the treaty loom over the war council.

     The Austrians would commence the battle with their Liebegarde (grenadiers and heavy cavalry) placed as a reserve behind the Vienna woods. Even the 2nd Provisional Korps was hidden from French view behind the screen of 1st Korps. Napoleon had anticipated the deployment (though he had expected the Liebegarde to also be in the defile between the woods). To the Austrians, this would be an attempt to protect the Landwehr and force the French to attack a wall of artillery on a narrow front. For Napoleon, this was an opportunity to emulate Friedland. By attacking aggressively into 1st Korps, he could force the Austrians back onto their reserves and have no option but to disorder those forces behind and crowd together, making it impossible for the Austrians to manoeuvre.

    The order that Napoleon would give initially is that the Imperial Guard would secure the corner of the Vienna Wood that was contested by Austrian light troops. I Corps would move behind the Guard to join with IV Corps in engaging the Austrian artillery line. At a time to be coordinated as the battle developed, the whole of the French army would simultaneously coordinate an attack against the Austrian line and then attack relentlessly to press them back. First though, cavalry and artillery still needed to arrive from St Polten. A heavy rain hung over the battlefield throughout the day, decreasing musket effectiveness.

By 1130 hrs, the French plan was evident. The Imperial Guard was already deep into the Vienna woods and had already sent a large brigade of Jäger running. The Grenzers would attempt to fall back through the woods before the Old Guard Grenadiers but their fate would be no better than the Jäger.

The Austrian artillery in the center, had likewise already sent some Bavarians routing to the rear. Ney, commander of IV Corps, had pushed the Bavarians into the center to absorb artillery fire and thereby preserve the French infantry. By this time, Napoleon had sent couriers to his subordinates setting 1230 as the time that he wanted all his divisions to be engaged at musket range and that 1300 hours was the hour appointed for the all-out attack.

Seeing the French plan, Charles has decided to commit his hidden reserve and the Liebegarde Corps arrives from the southern edge of the Vienna wood. They are a few hours yet from the French right flank but there is no right flank and Napoleon has ordered no troops to face this threat. Concentrate on the attack, his commanders are told.

At 1230 hrs, the wood has been cleared of Austrians and the Old Guard presses forward energetically. Artillery arriving for I Corps and the Guard, seeing that it will likely have no chance to deploy against Austrian I Corps, begins to set itself up to face the Liebegarde. As second Bavarian brigade has been routed by fire and the general for division will miss the upcoming attack, going back instead to rally. Reports would come out that Ney was not watching his watch.

Behind Austrian I Korps, the 2nd Provisional Korps is now visible to the French and also, two divisions of Landwehr cavalry arrive from Vienna to both support the line but also add to the mass behind it.

Another view of the center. On the left, Ney has sent in some cavalry as an opportunity presented itself and Gerard is a bit behind schedule but generally, the French are appearing to be well set up to launch the prepared attack.

The coordinated, aggressive attack across the front goes off almost as scheduled. It is only the Bavarians in the center that miss their timetable.

On the Austrian left, the flank movement by the Imperial Guard obliges the Austrians to swing three of their batteries about, almost back to back with those guns firing to the front. This would be the scene of a miraculous success for the Austrians where an infantry brigade would repulse a simultaneous attack by French light cavalry and grenadier infantry of the Young Guard. The grenadiers would be routed and it would be hours before they would get back into the fight.

Not every French attack was entirely successful, but overall, the effect was devastating to the Austrians. Some 50 artillery and five brigades of infantry are captured or routed.

Radetzky, meanwhile, is obliged to deploy his Corps in the face of a hastily thrown together French blocking force consisting of a Baden division and the cavalry and artillery of the Imperial Guard.

The French attack continues relentlessly forward in the center. In particular, the Imperial Guard and the 15th Division of IV Corps carve decisively into the flanks, hurling back everything that the Austrians attempt to put in their way. I Korps and 2nd Provisional Korps are both broken. Pockets of troops are left behind the the French advance. Without any orders, they can only remain in place and fight to defend themselves as best they can.

Archduke Charles leaves the center and rides with his small staff through the woods, past the still broken Young Guard grenadiers. Behind Charles, his Corps commanders would suffer poorly. Rosenburg would be captured and Fresnel killed. Two Austrian divisional commanders would also fall.

After little more than an hour, 2 Provisional Korps is routed from the field, returning broken to Vienna. I Korps and the Landwehr cavalry clings to the edge of the woods and tries to rally as the French attack moves past them. Napoleon though is furious at Pajol, the commander of 1st Cavalry Corps. He has not followed up the attack. He has missed an opportunity for glorious pursuit, and is instead distracted by the Austrian Liebegarde and begins to shift his divisions to the right. Similarly, Gerard's I Korps gets bogged down trying to solve the problem of a few isolated Austrian infantry brigades and does not pursue as aggressively as the French Emperor would wish.

Radetzky opens his attack up with two Grenadier brigades against the artillery of I Corps and the Baden infantry, along with 1st Cavalry Corps cavalry, counter attack to give them pause. The command of the Guard cavalry suffers with their corps commander several miles away leading the grenadiers in their pursuit of I Korps.

Not long after this, the Austrian heavy cavalry and French Guard Cavalry would meet in a desperate cavalry melee and both sides would fall back with heavy losses. The second wave of the Austrian attack would overrun the Guard horse artillery but leave it vulnerable to a counter-attack by fresh cavalry from the French 1st Cavalry Corps.

The Guard, along with the cavalry and one division of IV Corps continue to attack but Austrian I Korps has found opportunity to make some important rallies. They collect themselves and, despite sever command problems, try to organize a defense. A lot of Jager and Grenzer fire is poured into the Grenadiers but at that point the skies opened up with such a torrent of rains that the fighting had to be ended for the day.

Neither side would retreat. When the battle resumed the following day (automated), the Austrian army retreated badly damaged to Vienna. Napoleon's army was too damaged to dare pursuing to the capital.