Kaunitz was the third son of the statesman Wenzel Anton von Kaunitz-Rietberg and his wife, Mary Ernestine (née Countess Starhemberg). He remained unmarried.

Military career

Kaunitz was given a military education and volunteered to join the Austrian army at the beginning of the Seven Years' War as an ensign in the Trautmannsdorf Cuirassiers. He transferred to the Daun Infantry Regiment in 1759, and under Field Marshal Leopold Joseph von Daun rose to the position of Wing Adjutant, distinguishing himself at the Battle of Torgau, where he was severely wounded. After the peace of Hubertusburg in 1763, he was promoted to Colonel of the Baden Infantry Regiment (IR; later IR.23), and then in 1766 of the Emperor Joseph II Infantry Regiment (later IR.1). In 1773, he was promoted to General-Major. In the same year, he was appointed as Inhaber (Proprietor) of IR.38, followed in 1785 by IR.20. Promoted to Feldmarschall-Leutnant (FML) in 1783, he served as military commander in Croatia.

At the beginning of the Wars of the French Revolution, he was made Feldzeugmeister (FZM) in the Austrian Netherlands under Prince Josias of Saxe-Coburg-Saalfeld and served in the Flanders Campaign. Commanding Coburg's 27,000 man left wing, Kaunitz distinguished himself defending the line of the River Sambre in 1794, beating off Jacques Desjardin and Louis Charbonnier at the Battle of Grandreng on 13 May before completely routing the French at the Battle of Erquelinnes on 24 May. However, he resigned on 30 May after the Prince of Orange was appointed over his head for political reasons.^[1] Kaunitz commanded a column at the Battle of Fleurus on 26 June.

In 1796, he was made commanding general in Galicia and in 1805 in Moravia. The following year, he resigned from active service.

Death and legacy

As the last of the family line of Kaunitz-Rietberg, he died in Palais Kaunitz, Mariahilfer, and was buried in the family grave in Austerlitz.

Kaunitz was a member of the Masonic Lodge in Brno.