Andreas O ' Reilly von Ballinlough Andreas Graf O ' Reilly von Ballinlough ( 3 August 1742 – 5 July 1832 ) was an Austrian soldier and military commander of Irish origin . His military service extended through the Seven Years ' War , War of the Bavarian Succession , Austro - Turkish War , French Revolutionary Wars , and Napoleonic Wars . He retired from the army in 1810 and died at age 89 . Andrew O ' Reilly was born in Ballinlough , County Roscommon , Ireland . His brother , Hugh , was created baronet of Ballinlough in 1795 , and in 1812 , on the death of their maternal uncle John Nugent , he assumed by Royal licence the surname of Nugent ( see Nugent Baronets ) . Their sister Margaret married Richard Talbot and was , as a widow , created Baroness Talbot of Malahide in 1831 . At the age of 14 , Andrew O ' Reilly joined the army of Habsburg Austria and fought against the Kingdom of Prussia . After rising in the army , he married into an aristocratic family in his 40s . He led a cavalry regiment in combat against the Ottoman Turks . In the war with the First French Republic he was promoted to general officer . He played a leading role in the Battle of Marengo in 1800 , where he led one of the Austrian attack columns . Even in his 60s he remained a military officer , fighting against the First French Empire in 1805 and was compelled to surrender Vienna in 1809 . From 1803 until his death in 1832 , he was Proprietor ( Inhaber ) of an Austrian light cavalry regiment . Early career . He joined the army of Habsburg Austria as a volunteer in 1756 and fought in the Seven Years ' War . In the War of the Bavarian Succession , he achieved promotion to the rank of Major . In 1784 he wed Barbara Gräfin von Sweerts und Sporck ( 1760 – 1834 ) from a Bohemian noble family . That year he also rose in rank to Oberstleutnant . In 1787 he was ennobled , becoming Andreas Graf O ' Reilly von Ballinlough . In 1790 during the war against Turkey he was elevated to Oberst and took command of the " Modena " Chevau - léger Regiment # 13 , which he led at the Siege of Belgrade in late 1789 . French Revolutionary Wars . O ' Reilly was promoted to General - Major during the War of the First Coalition in 1794 . He achieved distinction at the Battle of Amberg on 24 August 1796 . At the First Battle of Zürich on 4 June 1799 , he led a brigade in Friedrich Freiherr von Hotze ' s Left Wing . His command consisted of one battalion of the " Peterwardeiner " Grenz Infantry Regiment # 9 , three battalions of the " Kaunitz " Infantry Regiment # 20 , two squadrons of the " Coburg " Dragoon Regiment # 6 , and two squadrons of Grenz Hussars . He transferred to the army of Michael von Melas in Italy and received promotion to Feldmarschallleutnant on 6 March 1800 . Napoleon Bonaparte invaded Italy across the Great St Bernard Pass in May 1800 and seized Milan on 2 June . Reacting to the surprise French offensive , Melas ordered O ' Reilly to take 3 , 000 troops and an artillery convoy to defend Piacenza . The Austrian army commander hoped to use Piacenza as a base to launch a counterattack against Milan . In the event , Piacenza fell to the French before O ' Reilly reached it . On 6 June , after an 11 - hour skirmish , he successfully managed to save the artillery convoy and withdraw to the west , while fending off a French column that tried to cut him off . At the Battle of Montebello on 9 June , Peter Karl Ott von Bátorkéz ordered O ' Reilly to hold the village of Casteggio with six battalions and four squadrons . When Jean Lannes advanced that morning , Ott was under instructions to avoid a battle . Yet , when he saw O ' Reilly ' s men come under attack , Ott ignored army Chief of staff Anton von Zach ' s advice and committed his corps to battle . O ' Reilly defended Casteggio stubbornly as the French persisted in their attacks for hours . Reinforced by Claude Perrin Victor , the French finally gained the upper hand and Ott called on O ' Reilly to cover the retreat . On 14 June at the Battle of Marengo Melas gave O ' Reilly command of the 3 , 000 - strong Right Column . The units under his leadership included single battalions of the " Banater " # 4 , " Warasdiner - Kreutzer " # 5 , " Oguliner " # 3 , and " Ottocaner " # 2 Grenz Infantry Regiments , plus one company of " Mariassy " Jägers . He also led detachments from three cavalry regiments , three squadrons of " Nauendorf " Hussars # 8 , two squadrons of Hussars # 5 , and one squadron of " Württemberg " Dragoons # 8 . On the afternoon of the 13th , O ' Reilly held Marengo village , which Melas intended to hold in preparation for his planned offensive the next day . In contrast to his stout defense of Casteggio , O ' Reilly ' s performance was weak and Victor captured Marengo after only an hour of fighting . The loss of the village meant that the Austrian army had to fight over the same ground the next day . On the morning of the 14th , the Advance Guard under Johann Maria Philipp Frimont and O ' Reilly ' s Right Column soon found Gaspard Amédée Gardanne ' s French division blocking their path . Gardanne ' s men , deployed on a narrow front , blunted the Austrian advance for 90 minutes and forced Melas to commit large forces to the attack . While the rest of the army hammered at the main French battle line near Marengo , O ' Reilly became preoccupied with Achille Dampierre ' s 300 to 400 Frenchmen who occupied Stortigliona Farm on the south flank . When the outnumbered defenders withdrew to the south , O ' Reilly , displaying " no initiative whatsoever " followed Dampierre . Ignoring the now - exposed French left flank , the Austrian Right Column hunted down Dampierre ' s force at Cassina Bianca . Dampierre finally surrendered to the " Oguliner " Grenz at 7 : 00 pm that evening after losing two - thirds of his men as casualties . But , the small French detachment tied up a significant part of O ' Reilly ' s column during the day Nevertheless , he earned the Knight ' s Cross of the Military Order of Maria Theresa on 18 August 1801 . Meanwhile , Melas finally cracked the French line near Marengo and organized a pursuit column . At about 3 : 00 pm , Konrad Valentin von Kaim ' s center column lurched into motion , with Ott ' s Left Column to the north and elements of O ' Reilly and Frimont ' s forces to the south . Late - arriving French reinforcements routed Kaim ' s center column around 5 : 00 pm . In the stampede that followed , O ' Reilly was able to retreat to the bridgehead successfully and covered the withdrawal of Ott ' s column that evening . Napoleonic Wars . In 1803 , he became Inhaber of the " O ' Reilly " Chevau - léger Regiment # 3 and held this position during his lifetime . The regiment became noted for its outstanding combat efficiency during the 1809 war . At the beginning of the War of the Third Coalition , O ' Reilly led a cavalry division in the " Armee von Italien " of Archduke Charles , Duke of Teschen . Under his command were the " Kaiser " Chevau - léger Regiment # 1 and " Kienmayer " Hussar Regiment # 8 , a total of 16 squadrons . In the Battle of Verona ( 1805 ) on 18 October 1805 , Count Heinrich von Bellegarde led his corps to support Josef Philipp Vukassovich , whose division was under attack by the French . O ' Reilly ' s division was only lightly engaged before darkness ended the fighting . At the Battle of Caldiero on 30 October , O ' Reilly ' s division participated in the counterattacks which helped restore the Austrian line . For his actions in the war , he earned the Commander ' s Cross of the Military Order of Maria Theresa on 28 May 1806 . In the War of the Fifth Coalition , Emperor Napoleon I of France defeated Johann von Hiller at the Battle of Landshut on 21 April 1809 and Archduke Charles at the Battle of Eckmühl on 22 April . These defeats left Hiller ' s outnumbered force isolated on the south bank of the Danube . Hiller ' s retreat left Vienna exposed to French capture . Accordingly , Archduke Maximilian of Austria - Este was given the task of garrisoning Vienna with the 35 , 000 available troops . O ' Reilly commanded 14 battalions of second - class Austrian and Bohemian landwehr plus 6 , 000 armed citizens . Other forces included a brigade of five elite grenadier battalions under Michael von Kienmayer ; Joseph Dedovich ' s division of eight regular , six landwehr , and six volunteer battalions ; and four battalions and five squadrons under Armand von Nordmann and Joseph , Baron von Mesko de Felsö - Kubiny . After a bombardment , the inexperienced Maximilian decided to abandon the capital and ordered O ' Reilly to surrender with a token garrison . The archduke mismanaged the evacuation and O ' Reilly capitulated on 13 May with 2 , 000 troops , including 13 generals , 17 staff officers , 163 officers . Even worse , the French recovered 100 pieces of artillery and a military chest with 4 . 5 million Gulden . O ' Reilly left the army on 7 January 1810 , being promoted to General der Kavallerie upon retirement . He died at Vienna on 5 July 1832 , only one month shy of his 90th birthday .