The Battle of Abensberg was fought on 20 April 1809, between an Allied force under the command of Emperor Napoleon I of France on one side and three Austrian corps led by Johann von Hiller, Archduke Louis of Austria, and Michael von Kienmayer. The Austrians formed the left wing of Archduke Charles, Duke of Teschen's main army and were under the overall command of Hiller. Napoleon's French troops, reinforced by troops from the Kingdom of Bavaria and the Kingdom of Württemberg outfought their opponents, inflicted heavy losses, and forced the Austrians to retreat to the southeast.