France / Austria, Napoleon I Bonaparte. 1809 medal commemorating the Battle of Aspern / Essling and the crossing of the Danube

The Battle of Aspern/Essling – May 22, 1809 
The Battle of Aspern was another major clash in the war between France and Austria, and also Napoleon’s second defeat. Archduke Charles, commander of the Austrian army, defeated at Regensburg, decided to abandon the defense of Vienna and withdrew all his forces across the Danube. Meanwhile, the enemy occupied the capital and then pursued the retreating enemy. From May 20 to 21, 1809, slightly over 30,000 men crossed the river via two bridges to the opposite bank. At that point, Archduke Charles decided to attack the weakened enemy. With over 75,000 soldiers at his disposal, he resolved to destroy both bridges and annihilate the units that had already crossed the river. Despite repeated assaults, the French managed to hold their bridgehead near Essling, though they lost Aspern. The destroyed bridges prevented Napoleon from sending reinforcements, but fortunately for the French, the Austrians failed to break through the enemy lines by the end of the day. During the night of the 21st to the 22nd, Napoleon ferried another 30,000 soldiers across to the opposite bank, and by morning he had decided to strike first and recapture Aspern. Despite partial success, the French troops came under heavy fire and were decimated by Austrian artillery. The main assault in the center collapsed, and Napoleon ordered his troops to retreat across the Lobau islet back to the right bank of the Danube. Casualties on both sides were enormous—the French lost nearly 30,000 men, while the Austrians lost 25,000. Many military historians compare the clash at Aspern to the Battle of Friedland, only with a different outcome to the detriment of the French.
source: historykon.pl