Kienmayer began his military career in 1774 as a cadet in the imperial Austrian Puebla de Portugalo Infantry Regiment # 26.

[1] During the Austro-Turkish War, Kienmayer excelled in a skirmish against a force of Turks that attacked the Austrian outposts in April 1788.

He fought in the Battle of Focșani on 21 July 1789 and received a promotion to Oberst-Leutnant in recognition of a successful raid carried out afterward.

He quickly returned to the front and executed another successful cavalry raid in November, capturing a senior Turkish officer.

He was also awarded the Military Order of Maria Theresa, Austria's highest honor for valor, on 21 December 1789 for bravery in the face of the enemy.

[1] Reassigned to the Barco Hussars, Kienmayer led the regiment in the Flanders Campaign in the War of the First Coalition beginning in April 1792.

[1] At the beginning of summer campaign of 1796 in southern Germany, Kienmayer led a brigade in the Army of the Lower Rhine under first Archduke Charles and later Wilhelm von Wartensleben.

[4] The following day he led a brilliant cavalry raid, capturing a large supply depot at Wertheim am Main and a small flotilla of munitions boats.

However, the leader of the Right-Center column, Ludwig Baillet de Latour, only gave weak support to Kienmayer's wing.

After Kollowrat's luckless corps was crushed, Moreau turned on the Austrian Right column, which still battled valiantly in the northern sector.

Kienmayer gave orders to retreat, and he and his generals brought their troops off intact, though Archduke Ferdinand lost 500 prisoners.

[8] During the chaotic retreat after Hohenlinden, Antoine Richepanse mauled Kienmayer's rear guard at Frankenmarkt on 17 December, inflicting 2,650 casualties on the Austrians.

[10] The battle plan called for Kienmayer to clear Tellnitz village of French troops and grab the high ground to the west of the Goldbach stream.

Stout resistance forced Kienmayer to commit both battalions of the 2nd Szekler Grenz Infantry Regiment before the knoll fell.

[12]Later in the battle, Kienmayer stubbornly covered Buxhowden's withdrawal after the French breakthrough on the Pratzen Heights forced the Allies into a disorganized retreat.

In June, Archduke Charles appointed Kienmayer to form the XI Corps from the raiding forces plus reinforcements.

The French tried to catch Kienmayer in a pincer, with Jérôme advancing from Leipzig and Jean-Andoche Junot moving from Frankfurt am Main.