George Olivier , count of Wallis George Olivier , Count of Wallis ( ; 1671 , Vienna - 19 December 1743 , Vienna ) was a field marshal of Irish descent in the service of the Holy Roman Empire and the Kingdom of the Two Sicilies and last regent of the Habsburg Kingdom of Serbia ( 1738 – 1739 ) . Born into an Irish family , he distinguished himself in Sicily by his capture of Messina . He then commanded on the Rhine ( 1733 ) , then in Italy and Hungary . He lost the decisive Battle of Grocka against the Ottoman Empire in 1739 , thus leading to the peace of Belgrade , which was unfavourable to Austria and thus led to his disgrace . Family . Ancestry . Georg Olivier ' s ancestor was Richard Wallis of Carrickmines , County Dublin , who became one of the first Irish officers in imperial service in 1632 . He died later that year after being wounded in the Battle of Lützen . Richard ' s eldest son Theobald returned to Ireland , with this branch of the family from then on taking the name Walsh , whilst his youngest son Olivier remained in the imperial Austrian army and became the founder of the Austrian Wallis branch before dying in 1667 as a major general in Hungary . Theobald ' s son , Feldzeugmeister Ernst Georg Wallis ( died 1689 ) was the father of George Olivier and his elder brother Franz Paul von Wallis ( died 1737 ) . Marriage and issue . George Olivier of Wallis married for the first time to Countess Maria Antonia of Götzen . After her death he married Maria Theresie , Countess of Kinsky auf Kunitz and Tettau . His only son and heir was Georg Stephan ( 19 July 1744 - 5 February 1832 ) . Life . After his father Ernst Georg Wallis ' s death in 1689 in the Nine Years ' War during the Siege of Mainz , George Olivier became a page at the Vienna court and just one year later became a lieutenant in the imperial army . In 1697 he fought as a hauptmann at the battle of Zenta . During the War of the Spanish Succession ( 1701 – 14 ) he first served in northern Italy ( rising to command a regiment as oberst in 1703 ) , then from 1707 in the conquest of Naples . He also served in Spain until 1713 and by the end of the war had reached the rank of Feldmarschall - Leutnants . He fought again in the Ottoman – Venetian War ( 1714 – 1718 ) , under the command of Prince Eugene of Savoy at the Battle of Petrovaradin on 5 August 1716 and at the sieges of Temesvár and Belgrade . The following year he was put in command of three regiments and posted to operations in Naples . In the War of the Quadruple Alliance ( 1718 – 20 ) he fought in the Austrian army on Sicily , being wounded in the struggle for Messina but later becoming governor of that city ' s fortress until 1727 , when he returned to Austria . When the Anglo - Spanish War ( 1727 – 1729 ) threatened to escalate the Holy Roman Emperor ordered Olivier back to Sicily to ready the island ' s defences . When no attack on Sicily came Olivier was dismissed in 1731 and from then until 1734 commanded the fortress at Mainz . In the War of the Polish Succession ( 1733 - 1735 / 38 ) he served against France in northern Italy ( from 1723 with the rank of Feldzeugmeister ) - he even took overall command of the whole Austrian force there for a time and won some advantages . In the Austro - Russian – Turkish War ( 1735 – 1739 ) he commanded an Austrian corps and was shortly afterwards promoted to field marshal . In the last year of the war he was the Austrian army ' s supreme commander but he lost the decisive battle of Grocka on 22 July 1739 . Only a week after the battle Austria was forced to sign the Peace of Belgrade , losing large swathes of territory to the Ottoman Empire . Olivier was one of the main culprits for the defeat , was tried with other generals before a war tribunal and on 22 February 1740 was sentenced to imprisonment at the fortress at Spielberg . On the death of Charles VI he was pardoned by Maria Theresa of Austria in November the same year . He then spent his final years on his lands , often being consulted by Vienna on military matters . The war against the Turks , however , had caused lasting damage to his brilliant military reputation , as is reflected in later historians ' assessments of him . Lands . In addition to the Bohemian estates of Kolešovice , Petrowice and Hochlibin , Olivier acquired or inherited several properties in the Grafschaft Glatz . He was lord of Wallisfurth ( ) , Seitenberg and Kunzendorf . On his brother Franz Paul ' s death in 1737 he inherited Plomnitz , Kieslingswalde , Glasegrund , Weißbrod , Altwaltersdorf , Kaiserswalde and Friedrichswald in Bohemia . His properties were inherited by his son Stephan ( died 1832 ) on his death in 1744 , though he sold Hassitz and Stolz to Friedrich Wilhelm , count of Schlabrendorf . He was the wartime and last governor of the Kingdom of Serbia , from November of 1738 until the accession of the crownland back to the Ottoman Empire in late 1739 according to the Treaty of Belgrade , from which it was carved out in accordance to the Treaty of Passarowitz in 1717 . Serbia was previously for a time governed from the Ottoman Empire between 1689 and 1691 , after the great defeat at Vienna during the Great Turkish War . A short - lived restoration of the Serbian Kingdom would follow during the Austro - Turkish war in 1788 during the occupation of those regions .