Charles Louis Auguste Fouquet , duc de Belle - Isle Charles Louis Auguste Fouquet , duc de Belle - Isle ( 22 September 1684 – 26 January 1761 ) was a French general and statesman . Life and career . Born in Villefranche - de - Rouergue , Belle - Isle was the grandson of Nicolas Fouquet , who served as Superintendent of Finances under Louis XIV . His family was in disgrace because of Fouquet ’ s brash ambition in the eyes of Louis XIV . Determined to blot out his family ’ s prior disgrace , he entered the army at an early age and was made proprietary colonel of a dragoon regiment in 1708 . He rose during the War of the Spanish Succession to the rank of brigadier , and in March 1718 to that of Maréchal de Camp . He was present at the capture of Fuenterrabía in 1718 and of San Sebastián in 1719 during the War of the Quadruple Alliance ( 1718 - 1720 . ) Aided by the rise of Cardinal Fleury , Belle - Isle was made lieutenant - général , and grew in influence over French military policy . In the War of the Polish Succession he commanded a corps under the orders of Marshal Berwick , capturing Trier and Traben - Trarbach and taking part in the Siege of Philippsburg in 1734 . When peace was made in 1736 , Louis XV gave Belle - Isle the governments of three important fortresses : Metz , Toul , and Verdun offices that he would hold until his death . This was in recognition of both his military services and of his taking part in the negotiations for the cession of Lorraine . Belle - Isle ’ s military and political reputation was now at its height , and he was one of the government ’ s principal advisers on military and diplomatic affairs . In 1741 he was sent on diplomatic mission to Frankfurt , Germany as French Plenipotentiary to carry out , in the interests of France , a grand scheme of political reorganization in the moribund empire , and especially to obtain the election of Charles Albert , Elector of Bavaria as emperor . The long tradition of Franco - Austrian rivalry had crystallized around Belle - Isle , who had emerged as the leader of the bellicose bloc of French policy makers towards the House of Austria . In the eventful year of 1741 , he was at the masthead of French interventionist policy in Germany — characterized by scholar Richard Lodge as a “ scheme for the humiliation of the House of Austria , ” — and of the beginnings of the War of the Austrian Succession . French aggression was in large part made possible by the precedent set by the Frederick II of Prussia and his conquest of Silesia — often referred to as the Rape of Silesia . France ’ s initial victories — including the election of Charles Albert to Holy Roman Emperor — were short lived , and by 1943 the war was proving to be very disappointing for France , as Belle - Isle ’ s military command in Germany was full of setbacks and losses . His aggressive strategy towards Austria was predicated on the swift defeat of an impotent and disorganized Austria , along with the lynchpin that was Franco - Prussian alliance . Belle - Isle was named Maréchal de France in 1741 and received control of a large army , with which it is said that he promised to make peace in three months under the walls of Vienna . The truth of this story is open to question , for no one knew better than Belle - Isle the limitations imposed upon commanders by the military and political circumstances of the times . He was , according to one scholar , “ the most important single influence on French policy in the crucial year of 1741 . ” However , the circumstances in which he found himself severely limited his efforts both as a general and as a statesman . Following his initial victories , Belle - Isle suffered regression and defeat . His aggressive policies had proved disastrous , however the daring French retreat from Prague would distinguish Belle - Isle ’ s military brilliance and bravery . In ten days he led 14 , 000 men — 5000 men stayed in the city under the command of François de Chevert — into and across the Bohemian Forest whilst being harassed by the enemy ’ s light cavalry and suffering great hardships . But by never allowing himself to be cut off , he was able to reach the relative safety of Eger , after losing 1500 men . His subordinate , François de Chevert , and his 5000 men , defended Prague so well that the Austrians allowed them to leave the city through an honourable capitulation . The means by which this was obtained supposedly included Chevert threatening to burn down the city . The campaign , however , had discredited Belle - Isle ; he was ridiculed in Paris and Fleury is said to have turned against him , and . To complete his misfortunes , he was taken prisoner by the English in going from Cassel to Berlin through Hanover . He was forced to remain a year in England , in spite of the demands of Louis XV and the Emperor Charles VII . During the French campaigns of 1746 - 47 , Belle - Isle was in command of the Army at Piedmont on the Alpine frontier . His troops conquered Antibes and Nice , only to suffer a decisive defeat at the Battle of Assietta . The disastrous battle would claim the life of Belle - Isle ’ s younger brother , the soldier and diplomatist , the Chevalier de Belle - Isle , who fought bravely as a French commander in the battle . Following the defeat , French forces were weakened and demoralized . However , Belle - Isle still managed to repel an invasion of Provence by Austrian and Italian forces and push the fighting back into the plain of Lombardy . At the peace , having thus retrieved his military reputation from the disasters of 1742 - 43 , Belle - Isle was made a Peer of France in 1748 . King Louis XV would make him Secretary of State for War in 1758 , a position Belle - Isle would hold until his death in 1761 . During his three years as Secretary of War , Belle - Isle undertook many reforms . Most Important was the development of a French military school for officers , seeing as the officer corps was shown to be inadequate during the wars of the past few decades . This included the suppression of the proprietary colonelcies of nobles who were too young to command ; and he instituted an Order of Merit . These reforms of the officer corps were similar to the structure of the Prussian army in that it attempted to place merit and honour above the blind appointments of nobility . The successfulness of his reforms is debated , because by this time the Seven Years ' War was in progress . According to one scholar , Walter L . Dorn , Belle - Isle ’ s efforts came “ too late to make a difference ” in the war and the continuing decline of French military power . Belle - Isle was a close friend of Count Saint - Germain and in 1760 allowed him to travel to The Hague in order to secure a peace treaty , obtain funding for France , and set up a whole separate company to manage France ' s treasury . The French Foreign Minister , Duc de Choiseul , was strongly against this and tried to have Count Saint - Germain arrested . Belle - Isle held an interest in literature throughout his life , and was elected a member of the French National Academy in 1740 ; so he founded the National Academy of Metz in 1760 . Also , Belle - Isle is regarded today as a builder - ruler . As benefactor of the city , he initiated during his dukedom the modernization of the centre of Metz in a context of Enlightenment . Belle - Isle awarded royal architect Jacques - François Blondel for the embellishment of the town square and the construction of the city hall , the parliament , and the guardhouse lodging . He also decided the edification of the royal Governor and Intendant palaces and the opera house of Metz , describing it as " one of the most beautiful France ' s opera - theater " at his time . Just before his death , he stated : " The city of Metz is my mistress . " However , his dukedom over Metz would end with his death because his only son , the Comte de Gisors , had been killed on June 23 , 1758 in the Battle of Krefeld . A commemorative plate honors him today on the forecourt of the opera house of Metz .