A powerful intrigue was urging the king to war.  Cardinal Fleury, prudent, economizing, timid as he was, had taken a liking for a man of adventurous, and sometimes chimerical spirit.  “Count Belle-Isle, grandson of Fouquet,” says M. d’Argenson, “had more wit than judgment, and more fire than force; but he aimed very high.”  He dreamed of revising the map of Europe, and of forming a zone of small states, destined to protect France against the designs of Austria.  Louis XV. pretended to nothing, demanded nothing for the price of his assistance; but France had been united from time immemorial to Bavaria:  she was bound to raise the elector to the imperial throne.  If it happened afterwards, in the dismemberment of the Austrian dominions, that the Low Countries fell to the share of France, it was the natural sequel of past conquests of Flanders, Lorraine, and the Three Bishoprics.  Count Belle-Isle did not disturb with his dreams the calm of the aged cardinal; he was modest in his military aspirations.  The French navy was ruined, the king had hardly twenty vessels to send to sea; that mattered little, as England and Holland took no part in the contest; Austria was not a maritime power; Spain joined with France to support the elector.  A body of forty thousand men was put under the orders of that prince, who received the title of lieutenant-general of the armies of the King of France.  Louis XV. acted only in the capacity of Bavaria’s ally and auxiliary.  Meanwhile Marshal Belle-Isle, the King’s ambassador and plenipotentiary in Germany, had just signed a treaty with Frederick II., guaranteeing to that monarch Lower Silesia.  At the same time, a second French army, under the orders of Marshal Maillebois, entered Germany; Saxony and Poland came into the coalition.  The King of England, George II., faithful to the Pragmatic-Sanction, hurrying over to Hanover to raise troops there, found himself threatened by Maillebois, and signed a treaty of neutrality.  The elector had been proclaimed, at Lintz, Archduke of Austria nowhere did the Franco-Bavarian army encounter any obstacle.  The King of Prussia was occupying Moravia; Upper and Lower Austria had been conquered without a blow, and by this time the forces of the enemy were threatening Vienna.  The success of the invasion was like a dream; but the elector had not the wit to profit by the good fortune which was offered him.  On the point of entering the capital abandoned by Maria Theresa, he fell back, and marched towards Bohemia; the gates of Prague did not open like those of Passau or of Lintz; it had to be besieged.  The Grand-duke of Tuscany was advancing to the relief of the town; it was determined to deliver the assault.