The enthusiasm in Paris and Vienna was enormous, and orders were despatched to the armies to set to, without further delay, and finish the work.

Fifteen thousand men were sent from Richelieu's army to reinforce Soubise, who thereupon issued from his mountain stronghold and marched against Leipzig.
Frederick, however, arrived there first, Ferdinand and Maurice joining him a day or two later; and while waiting there, Frederick received the joyful news that England requested him to appoint Duke Ferdinand, of Brunswick, commander-in-chief of the army until now commanded by the Duke of Cumberland, who had just sailed for England.
Pitt had now risen to almost absolute power in England, and was busied in reforming the abuses in the army and navy, dismissing incapable officials, and preparing to render some efficient aid to its hard-pressed ally.

The proposal that Prince Ferdinand should assume the command of the army--whose efforts had hitherto been rendered nugatory by the utter incompetence of the Duke of Cumberland who, although personally as brave as a lion, was absolutely ignorant of war--afforded immense satisfaction to the king.
No better choice could have been made.

Ferdinand was related to the royal families both of England and Prussia.

He was a capable general, prudent and at the same time enterprising, firm under difficulties, ready to seize opportunities; and under his command there was no doubt that the northern army, which had hitherto been useless, and had only been saved from absolute destruction by the incompetence of the French generals, would now play a useful part.
On October 30th Soubise, in spite of his orders to fight, and the fact that he had double the strength of the Prussians, fell back before them.