[Sidenote: Frederick's Victory at Rossbach, 1757]
Without waiting for a formal declaration of hostilities, Frederick seized Saxony, from which he exacted large indemnities and drafted numerous recruits, and, with his well-trained veteran troops, crossed the mountains into Bohemia. He was obliged by superior Austrian forces to raise the siege of Prague and to fall back on his own kingdom. Thence converged from all sides the allied armies of his enemies. Russians moved into East Prussia, Swedes from Pomerania into northern Brandenburg, Austrians into Silesia, while the French were advancing from the west. Here it was that Frederick displayed those qualities which entitle him to rank as one of the greatest military commanders of all time and to justify his title of "the Great." Inferior in numbers to any one of his opponents, he dashed with lightning rapidity into central Germany and at Rossbach (1757) inflicted an overwhelming defeat upon the French, whose general wrote to Louis XV, "The rout of our army is complete: I cannot tell you how many of our officers have been killed, captured, or lost." No sooner was he relieved of danger in the west than he was back in Silesia. He flung himself upon the Austrians at Leuthen, took captive a third of their army, and put the rest to flight.
The victories of Frederick, however, decimated his army. He still had money, thanks to the subsidies which Pitt poured in from Great Britain, but he found it very difficult to procure men: he gathered recruits from hostile countries; he granted amnesty to deserters; he even enrolled prisoners of war. He was no longer sufficiently sure of his soldiers to take the offensive, and for five years he was reduced to defensive campaigns in Silesia. The Russians occupied East Prussia and penetrated into Brandenburg; in 1759 they captured Berlin.
[Sidenote: French Reverses. The "Family Compact">[
The French, after suffering defeat at Rossbach, directed their energies against Hanover but encountered unexpected resistance at the hands of an army collected by Pitt's gold and commanded by a Prussian general, the prince of Brunswick. Brunswick defeated them and gradually drove them out of Germany. This series of reverses, coupled with disasters that attended French armies in America and in India, caused the French king to call upon his cousin, the king of Spain, for assistance. The result was the formation of the defensive alliance (1761) between the Bourbon states of France, Spain, and the Two Sicilies, and the entrance of Spain into the war (1762).
[Sidenote: Withdrawal of Russia]
What really saved Frederick the Great was the death of the Tsarina Elizabeth (1762) and the accession to the Russian throne of Peter III, a dangerous madman but a warm admirer of the military prowess of the Prussian king. Peter in brusque style transferred the Russian forces from the standard of Maria Theresa to that of Frederick and restored to Prussia the conquests of his predecessor. [Footnote: Peter III was dethroned in the same year; his wife, Catherine II, who succeeded him, refused to give active military support to either side.] Spain entered the war too late to affect its fortunes materially. She was unable to regain what France had lost, and in fact the Bourbon states were utterly exhausted. The Austrians, after frantic but vain attempts to wrest Silesia from Frederick, finally despaired of their cause.
[Sidenote: Treaty of Hubertusburg (1763): Humiliation of the Habsburgs and Triumph of the Hohenzollerns]
The treaty of Hubertusburg (1763) put an end to the Seven Years' War in Europe. Maria Theresa finally, though reluctantly, surrendered all claims to Silesia. Prussia had clearly humiliated Austria and become a first-rate power. The Hohenzollerns were henceforth the acknowledged peers of the Habsburgs. The almost synchronous treaty of Paris closed the war between Great Britain, on the one hand, and France and Spain on the other, by ceding the bulk of the French colonial empire to the British. Thereafter, Great Britain was practically undisputed mistress of the seas and chief colonial power of the world.
[Sidenote: Frederick the Great and the Partition of Poland]