Baron Franz von der Trenck Baron Franz von der Trenck ( German : " Franz Freiherr von der Trenck " , Croatian : " Barun Franjo Trenk " ) ( Reggio di Calabria . January 1 , 1711 – Brno . October 4 , 1749 ) was an Austrian soldier . Trenck was born into a military family on 1 January 1711 , in Reggio in south Italy , where his father Ivan Trenk served as an Austrian officer . Although born in Italy , Trenk was actually a Prussian with Austrian citizenship , and with large estates in Croatia , more precisely Slavonia . He spent his childhood mostly in Italy , Croatia and Hungary , which was not unusual since his father ' s job required frequent relocation . He was educated by the Jesuits at Oedenburg , and entered the Imperial army in 1728 but resigned in disgrace three years later and decided to live peacefully in Požega , Slavonia . He married and lived on his estate for a few years . Upon the death of his wife who had perished in the black plague of 1737 , he offered to raise an irregular corps of pandurs for service against the Turks , but this offer was refused , after which he entered the Russian army as a mercenary . But after serving against the Turks for a short time as captain and major of cavalry he was accused of bad conduct , brutality and disobedience and condemned to death . Despite showing insubordination he had gained popularity for defying an order to retreat . His sentence was commuted by Field Marschal Münnich to degradation and imprisonment . After a time Trenck returned to Austria , where his father was governor of a small fortress , but there he came into conflict with everyone and actually took sanctuary in a convent in Vienna . Prince Charles Alexander of Lorraine , interesting himself in this strange man , obtained for him an amnesty and a commission in a corps of irregulars . In this command , besides his usual truculence and bad manners , he displayed conspicuous personal bravery , and in spite of the general dislike into which his vices brought him his services were so valuable that he was promoted to lieutenant - colonel ( 1743 ) and colonel ( 1744 ) . Trenck earned most of his fame during the War of the Austrian Succession , as the leader and commander of a unit of pandurs , or paramilitary troops in the Austrian army which specialized in frontier warfare , guerrilla tactics and surprise hit - and - run actions , into which he recruited mostly Croatian mercenaries , experienced fighters from the Austro - Ottoman border . The Pandur soon became infamous for the atrocities they committed on the civilian population , some actions deemed brutal even by the standards of the day . When the War of the Austrian Succession broke out Trenck rallied volunteers and marched for Vienna to assist Maria Theresa of Austria . While in Vienna , Trenck ' s Pandurs marched the streets before invading Prussia . At the battle of Soor he and his irregulars plundered when they should have been fighting and Trenck was accused of having allowed the king of Prussia himself to escape . After a time he was brought before a court - martial in Vienna , which convicted him of having sold and withdrawn commissions to his officers without the permission of the empress , having punished his men without heed of the military code , and having drawn pay and allowance for fictitious men . Much was allowed to an irregular officer in all these respects , but Trenck had far outrun the admitted limits , and above all his brutalities and robberies had made him detested throughout Austria and Silesia . A death sentence followed , but the composition of the court - martial and its proceedings were thought to have been such as from the first forbade a fair trial , and the sentence was commuted by the Empress into one of cashiering and imprisonment . The rest of his life was spent in mild captivity in the fortress of Spielberg ( Špilberk in Czech ) in Brno , where he died on October 4 , 1749 . In his last will he left the sum of 30000 Gulden to the small town of Marienburg which had been sacked , burned and razed to the ground by his troops . Trenck ' s mummified remains can presently be seen on display in the crypt of Brno ' s Capuchin Monastery .