Bernhard Erasmus von Deroy Bernhard Erasmus von Deroy ( 11 December 1743 – 23 August 1812 ) from the Electoral Palatinate became a noted general officer in the army of Bavaria . His military career began shortly after the start of the Seven Years War . During the French Revolutionary Wars he first served on the side of the Coalition against the French revolutionaries , then fought as an ally of the First French Empire during the Napoleonic Wars . Deroy and his colleague , Karl Philipp von Wrede , were dominant personalities in the Bavarian military during the era of Napoleon Bonaparte . From a military family , Deroy entered the army as a junior officer at an early age . He rose in rank to become a general by the time the War of the First Coalition broke out . He defended his home city of Mannheim against the army of the First French Republic until its capture in 1795 . In 1800 , he again fought as an ally of Austria , leading a brigade of Bavarian troops in action . From the time Napoleon became the emperor of France , Bavaria became allied to France and Deroy capably led a division during the 1805 , 1806 – 1807 , 1809 , and 1812 wars . He was mortally wounded in 1812 during Napoleon ' s campaign in Russia . Early career . Born in Mannheim on 11 December 1743 , Bernhard Erasmus von Deroy ' s parents were General Matthias Bertram de Roy and Elizabeth Christine of Hofstatt . He was appointed ensign in the " Count Palatine Karl August " Infantry Regiment at a very young age and fought in the Battle of Hastenbeck on 27 June 1757 . He became a lieutenant on 14 February 1761 and captain of an infantry company on 5 September 1763 . His next promotion occurred on 30 October 17705 when he became a major in the " Duke of Zweibrücken " Infantry Regiment . He was elevated in rank to Oberstleutnant while belonging to the " Rodenhausen " Infantry Regiment on 8 June 1784 . On 21 December 1787 he returned to the " Duke of Zweibrücken " as Oberst and commanding officer . On 3 November 1792 , Deroy was promoted to " General - Feldwachtmeister " and later appointed governor of Mannheim . In this position he became responsible for strengthening the fortifications in anticipation of a French attack . French Revolutionary Wars . On 23 and 24 December , Deroy fought in the bridgehead of Mannheim , which had come under attack . On 25 December the bridgehead fell to the French and four Austrian battalions became prisoners . The fortress came under siege the following year and Lieutenant General Baron von Belderbusch capitulated on 20 September 1795 . The French captured the 9 , 200 - man garrison and 471 guns , of which all were Bavarians except one Austrian battalion . Deroy left the city on 22 September after agreeing not to serve in the war against France . The War of the Second Coalition broke out in 1799 and in the spring of 1800 , Lieutenant General Christian Zweibrücken appointed Deroy to lead the 6 , 000 - strong 1st Brigade as part of a German auxiliary corps allied with the Austrians . Deroy ' s command included the following battalions , " Reuss " Grenadiers , " Elector of Bavaria " , " Morawitzky " , " Herzog Wilhelm " , " Schlossberg " , plus a company of sharpshooters , three squadrons of Chevau - légers , a battery of foot artillery and a battery of horse artillery . On 12 May , the 2nd Brigade led by Karl Philipp von Wrede joined the corps . He fought at the Battle of the Iller River on 5 June and at the Battle of Neuburg an der Donau on 27 June . The series of Austrian defeats was ended by a truce on 15 July 1800 . The armistice concluded in late November at which time the youthful and inexperienced Austrian commander Archduke John of Austria assembled 15 , 762 Bavarians and Württembergers behind the Inn River west of Braunau am Inn . John ' s 65 , 500 - man main body lay just to the east . In Zweibrücken ' s Bavarian Division , Deroy led the " Reuss " Grenadiers , " Metzen " Light , " Schlossburg " , " Stengel " , and " Minucci " infantry battalions . With Wrede ' s brigade , the Bavarian contingent numbered 7 , 017 infantry , 828 cavalry , and 26 artillery pieces . In the Battle of Hohenlinden on 3 December 1800 , the Bavarians marched with the Left Center Column , which was under the command of Johann Kollowrat and accompanied by Archduke John . Early in the morning , Kollowrat drove back the French 108th Line Infantry Demi - Brigade . To keep the attack rolling , the Austrian committed three of Deroy ' s battalions . However , the allies soon ran into Emmanuel Grouchy ' s main line of resistance and were driven back by a powerful counterattack . Zweibrücken also sent two Bavarian battalions searching for Johann Sigismund Riesch ' s tardy Left Column to the south . Instead of Riesch , Antoine Richepanse ' s French division emerged from the forests to Kollowrat ' s left rear . After heavy fighting , Kollowrat ' s column was caught in a three - sided trap between the divisions of Richepanse , Grouchy , and Michel Ney . In the disaster that followed , Deroy and 18 other Bavarian officers became prisoners of war along with thousands of Austrian and Bavarian rank and file . Zweibrücken had to catch an artillery horse in order to get away and even the archduke had a narrow escape . Napoleonic Wars . 1805 – 1807 . In 1801 Elector Maximilian IV Joseph of Bavaria named Deroy to a commission to improve and reorganize the army . He led a brigade at Landshut in 1803 , and in the following year he and Wrede introduced the new military regulations . On 21 April 1804 , Deroy received promotion to Lieutenant General and was decorated with military awards . Napoleon awarded him the Grand Eagle of the Legion d ' Honneur . The latter award was possible because Bavaria became a secret ally of France against Austria . When the War of the Third Coalition broke out in September 1805 , the Bavarian army withdrew north to the Main River in response to the Austrian invasion . Deroy commanded a corps of two divisions , including his own and Wrede ' s . The French armies soon obliterated the Austrian army of Karl Mack von Lieberich at the Battle of Ulm on 20 October . This freed the Bavarian contingent to operate against the Tyrol . On 1 November , Bavarian Oberst Pompei successfully rushed several positions near Lofer which lies southwest of Salzburg . Encouraged , Deroy ordered an attack on the Strub Pass , eight kilometers west of Lofer . The position was defended by Franz Xaver Saint - Julien ' s 1 , 500 - man Austrian brigade with the support of local Tyrolean militia and sharpshooters . The assault ended in a bloody repulse , with 1 , 200 to 1 , 800 Bavarians out as casualties , including Deroy wounded . Saint - Julien only lost 200 men and one cannon . On 1 March 1806 , Deroy received the Grand Cross of the Military Order of Max Joseph . In the War of the Fourth Coalition , Deroy was placed under the command of Prince Jerome Bonaparte . He undertook several sieges of Prussian fortresses in Silesia during 1806 and 1807 . In November 1806 , Deroy ' s 1st Bavarian Division laid siege to the fortress of Głowgów ( Glogau ) . After the Bavarians were replaced by a Württemberg division , the place surrendered on 2 December . He marched to Wrocław ( Breslau ) where his division arrived on 18 December . Prince Jerome ' s 22 , 000 - strong IX Corps maintained the siege until 6 January 1807 when the fortress capitulated with 5 , 300 prisoners and 268 cannon . Bavarian casualties numbered 259 in the operation . Deroy then advanced with 13 , 000 troops to lay siege to Brzeg ( Brieg ) . On 17 January Brzeg surrendered with 1 , 450 prisoners . Deroy placed Koźle ( Kosel ) under siege on 24 January , but the place resisted all attempts at capture . On 2 July , the Bavarians abandoned the effort . Now under the command of Dominique Vandamme , Deroy participated in the storm and capture of Kłodzko ( Glatz ) on 24 June 1807 . He moved against Srebrna Góra ( Silberburg ) with 6 , 500 troops , but the Prussian garrison refused to give up after he bombarded the fortress on 28 and 29 June . The Peace of Tilsit ended the fighting . On 27 November , he was named to the Privy Council of Bavaria . 1809 and 1812 . At the beginning of the War of the Fifth Coalition , Deroy relinquished command of the 1st Division to Crown Prince Ludwig of Bavaria and took charge of the 3rd Division in the VII Corps . This unit consisted of the 5th , 9th , 10th , and 14th Infantry Regiments , the 5th and 7th Light Battalions , the " Taxis " Dragoons and " Bubenhoven " Chevau - légers , and 18 pieces of artillery . After the Austrian invasion , Deroy held the west bank of the Isar River opposite Landshut on 16 April 1809 . In a brief action , each side lost 150 to 200 killed and wounded . After an Austrian column crossed upstream at Moosburg , he fell back through Pfeffenhausen to Siegenburg . Under the command of Marshal François Joseph Lefebvre , Deroy was present but not engaged in the Battle of Abensberg on 20 April . On 21 April , as Napoleon was winning the Battle of Landshut to the south , Deroy fought against Prince Franz Seraph of Rosenberg - Orsini ' s Austrian IV Armeekorps . He advanced on the right flank of Louis Davout ' s French III Corps and captured the village of Schierling . The Bavarians got no farther that day and Davout ' s attacks were also stopped . Bavarian losses were about 150 and French casualties 1 , 500 , while the Austrians lost 3 , 000 . In the Battle of Eckmühl on 22 April , Davout and Deroy advanced from the west , while Napoleon fell on Rosenberg ' s position from the south . The Austrians held a key position called the Bettel Berg with 3 , 000 infantry and 16 cannons . Deroy ' s cavalry brigade under General - Major Seydewitz attacked first and was driven back by well - handled Austrian light cavalry . Deroy ' s infantry tried next . Raked by accurate artillery fire and counterattacked by cavalry , they too were defeated . Later in the day , three squadrons of Bavarian cavalry charged again and were mowed down by artillery fire . But as the survivors fell back from the deadly guns , a mass formation of French cuirassiers trotted forward . The heavy cavalrymen swept aside a last despairing Austrian cavalry charge and overran the Bettel Berg . Elements of Deroy ' s cavalry brigade participated in the famous moonlight cavalry action at Alteglofsheim that night . After Eckmühl and the minor Battle of Neumarkt - Sankt Veit on 24 April , Napoleon urged Lefebvre to seize Salzburg and relieve the Bavarian garrison of the Kufstein Fortress . In early May , Austrians and Tyrolean irregulars defeated General - Major Vincenti ' s brigade of the 3rd Division in its attempt to reach Kufstein . At this , Napoleon demanded that Lefebvre mount a full - scale relief operation . On 11 May , Deroy relieved the 576 - man garrison , which had held out for a month . With Wrede ' s and Deroy ' s divisions , Lefebvre routed Johann Gabriel Chasteler de Courcelles at the Battle of Wörgl on 13 May . Chasteler , who had been supporting the Tyrolean Rebellion , was soon after ordered to abandon the area . Innsbruck was occupied but Deroy ' s 3rd Division came under attack in the first of the Battles of Bergisel on 25 May 1809 . Out of 4 , 000 soldiers and 12 guns , the Bavarians lost from 20 to 70 dead and from 100 to 150 wounded . The Austrians and Tyroleans under Andreas Hofer suffered 50 dead and 30 wounded . Discouraged by the lack of local support , the Tyroleans withdrew to the south . They returned to attack again on 29 May in the second battle . Deroy ' s 5 , 240 soldiers and 18 guns held their ground , losing 87 dead , 156 wounded , and 53 missing . The 1 , 200 Austrian regulars and 13 , 600 Tyroleans lost 90 dead and 160 wounded . Low on ammunition and food , Deroy evacuated Innsbruck on 30 May and retreated to Kufstein . After Napoleon ' s victory in the Battle of Wagram on 5 and 6 July , Lefebvre and Deroy reoccupied Innsbruck . In the third battle of Bergisel on 13 August , 18 , 000 Tyroleans sharply defeated Deroy ' s 3 , 000 troops . The Bavarians suffered 200 dead and 250 wounded while the irregulars lost 100 dead and 220 wounded . After taking hostages , Lefebvre ordered another retreat and the Tyrol was cleared of Bavarians by 18 August . On 17 October , the Tyroleans were surprised and badly beaten at Bodenbichl by General - Major Rechberg . After this , the three divisions of VII Corps retook the Tyrol . The fourth battle of Bergisel was fought and won by Wrede ' s troops on 1 November and the rebellion was stamped out . Deroy was promoted to General of Infantry on 1 January 1811 . When Napoleon invaded the Russian Empire in 1812 , Deroy commanded the 19th Infantry Division in Laurent de Gouvion Saint - Cyr ' s VI Corps . A discouraged Deroy wrote to King Maximilian Joseph on 22 June that he did not see how they would survive . The march into Russia was difficult and the Bavarian general reported to his king that the food was bad and the soldiers ' uniforms and shoes had worn out . Because of this , he wrote , discipline was breaking down and the troops were depressed and insubordinate . The First Battle of Polotsk began on 16 August , with Marshal Nicolas Oudinot commanding the II and VI Corps against Peter Wittgenstein ' s Russian I Corps . On the first day , the 30 , 000 Russians defeated the 24 , 000 Allies and Oudinot was wounded . Saint - Cyr took command and withdrew most of his troops to the south bank of the Daugava River on 17 August . He then built a concealed bridge and secretly shifted his small army to the north bank on the night of 17 – 18 August . At 3 : 00 PM , Saint - Cyr attacked the surprised Russians with the Bavarian VI Corps on the right , the French II Corps in the center , and the French cavalry on the left . Covered by a bombardment from 30 cannons , Deroy ' s 19th Division stormed the village of Spas while Wrede ' s 20th Division attacked farther to the right . During the attack , Deroy was hit in the abdomen by a musket ball . He continued to lead his troops during the battle , but died of his injury on 23 August 1812 . He was buried at the Saint Xavier Church in Polotsk . In recognition of his services , an order of nobility was bestowed on his wife and oldest son .