On the morning of 23 April in the Battle of Ratisbon, there was another wild cavalry melee between 56 squadrons of Austrian horsemen and the French cavalry of Nansouty, Saint-Sulpice and Louis-Pierre Montbrun. The struggle went on for two hours before the Austrians withdrew. On 15 May, the 1st Cuirassiers numbered 527 troopers. At the Battle of Aspern-Essling on 21–22 May, the division of Saint-Sulpice reached the battlefield late on the first day as Napoleon found himself with 31,400 soldiers facing 100,000 Austrians with a river at his back. Reinforced in the night to 50,000 infantry, 12,000 cavalry and 144 guns, Napoleon ordered an advance by his infantry and cavalry on the Austrian center. This attack pressed back the Austrians until their army commander Archduke Charles, Duke of Teschen led forward the Reserve Corps. Despite a series of cavalry charges, the French were pushed back into their small bridgehead and forced to retreat that night.