As a mercenary leader, he served Emperor Friedrich III. several great services, in particular he defended Wiener Neustadt in 1452 against the estate army. He was rewarded princely for this and was given the right to mint his own coins as well as permission to found a town next to his Schlaining Castle .
From 1453 to 1457 he served the Hungarian-Bohemian King Ladislaus Postumus . Both in the Hungarian royal election (February 12, 1459)  as in a revolt of the Viennese citizens (1462) Baumkircher and his people were on the side of Emperor Frederick III.
In 1469, however, he turned against the emperor and, together with the Hungarian King Matthias Corvinus, organized an uprising of the Styrian nobility against Friedrich III. The so-called Baumkircher feud  began with the delivery of the feud letter of the Styrian noble union to Friedrich III. on February 1, 1469. The aristocratic union under the leadership of Baumkircher and Johann von Stubenberg occupied the Styrian towns of Hartberg , Fürstenfeld , Feldbach , Marburg , Windischfeistritz , Gonobitz and Wildon Castle. In March 1469 Baumkircher's troops occupied the Mürz Valley , but in April 1469 they lost Scheifling , Oberkapfenberg , Schwanberg and Oberradkersburg to the Imperial troops. On July 21, 1469, at the Battle of Fürstenfeld , the troops of Baumkircher and Emperor Friedrich III met, in which Baumkircher inflicted a heavy defeat on the imperial troops. Baumkircher's troops carried out raids as far as the Graz area .
In October 1469, an armistice between Friedrich III. and Baumkircher agreed. On June 30, 1470, Friedrich III. a contract with Baumkircher, which promised him complete amnesty and payment of 14,000 florins . In the fall of 1470, Baumkircher rose again against Emperor Friedrich III for failure to make payments.
On April 23, 1471, Baumkircher and Andreas von Greisenegg went to Graz for negotiations after they had been promised safe conduct until the vesper bell rang . That day the bell rang an hour earlier and both were arrested. In the evening they were publicly beheaded in front of the Murtor without a trial .
- Catholic parish church Stadtschlaining with a Pauline monastery in Stadtschlaining in today's Burgenland
Due to the imperial resolution of Franz Joseph I of February 28, 1863, Andreas Baumkircher was added to the list of the "most famous warlords and generals of Austria worthy of perpetual emulation", in whose honor and memory there was also a life-size statue in the general hall of the then new The Imperial and Royal Court Weapons Museum (today: Heeresgeschichtliches Museum Wien ) was built. The statue was created in 1872 by the sculptor Vincenz Pilz (1816–1896) from Carrara marble and was dedicated by Emperor Franz Joseph himself. 
- Franz Krones : Baumkircher, Andreas . In: Allgemeine Deutsche Biographie (ADB). Volume 2, Duncker & Humblot, Leipzig 1875, p. 169 f.
- Hans Wagner: New German Biography (NDB). Volume 1, Duncker & Humblot, Berlin 1953, ISBN 3-428-00182-6 , p. 668 ( ). In:
- Burgenland State Museum (ed.): Andreas Baumkircher and his time (= scientific work from Burgenland . Volume 67). Eisenstadt 1983 ISBN 3-85405-085-2 , PDF on ZOBODAT
- August Ernst: History of Burgenland. Oldenbourg Wissenschaftsverlag, 2nd edition of March 24, 1992, ISBN 3-4865-4072-6 , p. 95.
- The Baumkircher feud in the Atlas Burgenland. In: atlas-burgenland.at.
- Johann Christoph Allmayer-Beck : The Army History Museum Vienna. The museum and its representative rooms. Kiesel Verlag, Salzburg 1981, ISBN 3-7023-0113-5 , p. 30.
|ALTERNATIVNAMEN||Baron von Schlaining|
|SHORT DESCRIPTION||Austrian military leader|
|DATE OF BIRTH||one 1420|
|PLACE OF BIRTH||uncertain: Wippach (Vipava), Slovenia|
|DATE OF DEATH||23. April 1471|
|Place of death||Graz|