Baron Franjo Jelačić Bužimski was a Croatian military officer and nobleman, a member of the House of Jelačić. He began his service in the Habsburg army as a Grenz infantry officer and fought against the Ottoman Empire. During the French Revolutionary Wars he received promotion to the rank of general officer and won an outstanding victory at Feldkirch. His later career proved that his martial abilities were limited. He twice led independent division-sized forces in the Napoleonic Wars, with unhappy results. He was Proprietor (Inhaber) of an Austrian infantry regiment from 1802 until his death.

The Battle of Abensberg took place on 20 April 1809 between a Franco-German force under the command of Emperor Napoleon I of France and a reinforced Austrian corps led by Feldmarschall-Leutnant Archduke Louis of Austria. As the day wore on, Feldmarschall-Leutnant Johann von Hiller arrived with reinforcements to take command of the three corps that formed the Austrian left wing. The action ended in a complete Franco-German victory. The battlefield was southeast of Abensberg and included clashes at Offenstetten, Biburg-Siegenburg, Rohr in Niederbayern, and Rottenburg an der Laaber. On the same day, the French garrison of Regensburg capitulated.