The Austrian army is defeated by the First French Empire army led by Napoleon and driven over the Danube in Regensburg.

The Battle of Ratisbon, also called the Battle of Regensburg, was fought on the 22 April 1809, during the Napoleonic Wars, between the army of the First French Empire, led by Napoleon I, and that of the Austrian Empire, led by Archduke Charles. Scene of the last engagement of the Bavaria phase of the campaign of 1809, the brief defense of the city and installation of a pontoon bridge to the east enabled the retreating Austrian army to escape into Bohemia. During the assault, Marshal Jean Lannes led his troops up ladders onto the walls, and Napoleon was wounded in his ankle by a small artillery round. The shot had been fired at great distance and did not severely hurt the Emperor, but caused a contusion.

At dawn on 23 April the French advance continued in a pincer movement toward Ratisbon, with General Louis-Pierre Montbrun coming from the southwest and Napoleon moving up from the south. Around 9:00 A.M. 10,000 French cavalry, led by General Étienne Nansouty’s two cuirassier divisions, began to engage the Austrian cavalry, who despite poorly coordinated charges were able to hold them for almost three hours to facilitate the army’s escape, before they slipped away. Only then did the French discover the pontoon bridge, but its last defenders were able to hold on and cut the securing ropes to prevent the French from using it.

French casualties, including a wounded-in-the-ankle Bonaparte, were between 1,500 and 2,000 while the Austrians lost at least 6,000 men killed, injured or captured. Sending Marshal Louis Davout to guard the north bank across the Danube, Bonaparte was now free to move on Vienna.