The confederates endeavoured to keep their plans profoundly secret till they were ready to burst at once on the devoted King of Prussia; but Frederick was the last man alive to be taken by surprise. The secret was soon betrayed to him, and, at once waiving his dislike of the King of England, he concluded a convention with him in January, 1756, and bound himself, during the disturbances in America, not to allow any foreign troops to pass through any part of Germany to those colonies, where he could prevent it. Having his treasury well supplied, he put his army in order, and in August of that year sent a peremptory demand to Vienna as to the designs of Austria, stating, at the same time, that he would not accept any evasive reply; but the reply being evasive, he at once rushed into Saxony at the head of sixty thousand men, blockaded the King of Saxony in Pirna, and secured the queen in Dresden. By this decisive action Frederick commenced what the Germans style "The Seven Years' War." In the palace of Dresden Frederick made himself master of the secret correspondence and treaties with France, Russia, and Austria, detailing all their designs, which he immediately published, and thus fully justified his proceedings to the world. The Austrians advanced under Marshal Braun, an officer of English extraction, against Frederick, but after a hard-fought battle at Lowositz, on the 1st of October, Frederick beat them, and soon after compelled the Saxon army, seventeen thousand strong, to surrender at Pirna. The King of Saxony, who had taken refuge in the lofty rock fortress of Königstein, surrendered too, on condition of being allowed to retire to Warsaw, and Frederick established his headquarters for the winter at Dresden, levying heavy contributions throughout Saxony. During this year little was done in America. General Bradstreet defeated a body of the enemy on the River Onondaga, and, on the other hand, the French took the two small forts of Ontario and Oswego.