His operations were no more than a demonstration, and had so little effect that Broglie was sent for in haste to take over the command from him, Belleisle at the same time taking over charge of the army at Prague. Broglie's command was now on the Danube, east of Regensburg, and the imperial (chiefly Bavarian) army of Charles VII. under Seckendorf aided him to clear Bavaria of the Austrians. This was effected with ease, for Khevenhüller and most of his troops had gone to Bohemia. Prince Charles and Khevenhüller now took post between Linz and Passau, leaving a strong force to deal with Belleisle in Prague. This, under Prince Lobkowitz, was little superior in numbers or quality to the troops under Belleisle, under whom served Saxe and the best of the younger French generals, but its light cavalry swept the country clear of provisions. The French were quickly on the verge of starvation, winter had come, and the marshal resolved to retreat. On the night of the 16th of December 1742, the army left Prague to be defended by a small garrison under Chevert, and took the route of Eger. The retreat (December 16-26) was accounted a triumph of generalship, but the weather made it painful and costly.
The brave Chevert displayed such confidence that the Austrians were glad to allow him freedom to join the main army. The cause of the new emperor was now sustained only in the valley of the Danube, where Broglie and Seckendorf opposed Prince Charles and Khevenhüller, who were soon joined by the force lately opposing Belleisle.
In Italy, Traun held his own with ease against the Spaniards and Neapolitans. Naples was forced by a British squadron to withdraw her troops for home defence, and Spain, now too weak to advance in the Po valley, sent a second army to Italy via France. Sardinia had allied herself with Austria, and at the same time neither state was at war with France, and this led to curious complications, combats being fought in the Isère valley between the troops of Sardinia and of Spain, in which the French took no part.
6. The Campaign of 1743 opened disastrously for the emperor. The French and Bavarian armies were not working well together, and Broglie and Seckendorf had actually quarrelled. No connected resistance was offered to the converging march of Prince Charles's army along the Danube, Khevenhüller from Salzburg towards southern Bavaria, and Prince Lobkowitz (1685-1755) from Bohemia towards the Naab. The Bavarians suffered a severe reverse near Braunau (May 9, 1743), and now an Anglo-allied army commanded by King George II., which had been formed on the lower Rhine on the withdrawal of Maillebois, was advancing southward to the Main and Neckar country. A French army, under Marshal Noailles, was being collected on the middle Rhine to deal with this new force. But Broglie was now in full retreat, and the strong places of Bavaria surrendered one after the other to Prince Charles. The French and Bavarians had been driven almost to the Rhine when Noailles and the king came to battle. George, completely outmanoeuvred by his veteran antagonist, was in a position of the greatest danger between Aschaffenburg and Hanau in the defile formed by the Spessart Hills and the river Main. Noailles blocked the outlet and had posts all around, but the allied troops forced their way through and inflicted heavy losses on the French, and the battle of Dettingen is justly reckoned as a notable victory of the British arms (June 27). Both Broglie, who, worn out by age and exertions, was soon replaced by Marshal Coigny (1670-1759), and Noailles were now on the strict defensive behind the Rhine. Not a single French soldier remained in Germany, and Prince Charles prepared to force the passage of the great river in the Breisgau while the king of England moved forward via Mainz to co-operate by drawing upon himself the attention of both the French marshals.
The Anglo-allied army took Worms, but after several unsuccessful attempts to cross, Prince Charles went into winter quarters. The king followed his example, drawing in his troops to the northward, to deal, if necessary, with the army which the French were collecting on the frontier of Flanders. Austria, England, Holland and Sardinia were now allied. Saxony changed sides, and Sweden and Russia neutralized each other (peace of Abo, August 1743). Frederick was still quiescent; France, Spain and Bavaria alone continued actively the struggle against Maria Theresa.
In Italy, the Spaniards on the Panaro had achieved a Pyrrhic victory over Traun at Campo Santo (February 8, 1743), but the next six months were wasted in inaction, and Lobkowitz, joining Traun with reinforcements from Germany, drove back the enemy to Rimini. The Spanish-Piedmontese war in the Alps continued without much result, the only incident of note being a combat at Casteldelfino won by the king of Sardinia in person.
7. Campaign of 1744. - With 1744 began the Second Silesian War. Frederick, disquieted by the universal success of the Austrian cause, secretly concluded a fresh alliance with Louis XV. France had posed hitherto as an auxiliary, her officers in Germany had worn the Bavarian cockade, and only with England was she officially at war. She now declared war direct upon Austria and Sardinia (April 1744). A corps was assembled at Dunkirk to support the cause of the Pretender in Great Britain, and Louis in person, with 90,000 men, prepared to invade the Austrian Netherlands, and took Menin and Ypres. His presumed opponent was the allied army previously under King George and now composed of English, Dutch, Germans and Austrians. On the Rhine, Coigny was to make head against Prince Charles, and a fresh army under the prince de Conti was to assist the Spaniards in Piedmont and Lombardy. This plan was, however, at once dislocated by the advance of Charles, who, assisted by the veteran Traun, skilfully manoeuvred his army over the Rhine near Philipsburg (July 1), captured the lines of Weissenburg, and cut off the French marshal from Alsace. Coigny, however, cut his way through the enemy at Weissenburg and posted himself near Strassburg. Louis XV. now abandoned the invasion of Flanders, and his army moved down to take a decisive part in the war in Alsace and Lorraine. At the same time Frederick crossed the Austrian frontier (August).