In 1740, Frederick had ascended the throne. He was at Potsdam, and confined to his chamber by illness, when the death of the Emperor Charles was announced to him. This event broke up the peace of Germany. The Emperor, Charles VI., having no issue after a marriage of four years, established a new law of succession, known as the Pragmatic Sanction. The heirship of Austria had hitherto been limited to males; but, by the new law, the undivided monarchy was to devolve first to his own daughters, or, if they should not be living at the time of his death, to the daughters of his elder brother Joseph, Electresses of Saxony and Bavaria, and so on, always to the nearest relatives. The death of the Emperor obviously threatened to involve all Europe, and especially Germany, in convulsion; for the mere publication of the Pragmatic Sanction, in 1724, had produced counter declarations from no less than three princes of the empire, who regarded their rights as invaded. The Elector of Bavaria, who was married to a daughter of the Emperor Joseph I., founded a claim to the Austrian dominions on the will of Ferdinand I.; France was disposed to enter into an alliance with Prussia; Sweden and Russia would have been inevitably involved in the war. And it was of this complication of events that the young Prussian monarch took advantage to make an assault upon Austria. For one hundred years Prussia had complained of the loss of Silesia. Her successive kings had severally impeached its seizure by Austria, and the Great Elector had still earlier bequeathed the recovery of the province to the gallantry, or the good fortune, of his successors. Frederick, now at the head of a powerful army, with a full treasury, and seeing an approaching contest for the possession of Austria itself, regarded this as a favourable moment for the recovery of his ancestral territory. Frederick, having now completed all his preparations, sent an envoy to Vienna, to offer his alliance to Maria-Theresa, and his vote to her husband at the election of emperor, provided she would give up Silesia. But knowing the contempt with which the Austrian cabinet regarded the minor princes of Germany, and also knowing the advantage of promptitude, where the object is possession, he at once set his army in motion for the Silesian frontier. His proposal was, as he had foreseen, rejected; and on its rejection, without a moment's delay, he rushed over the frontier. He found, as he had expected, the Austrian government wholly unprepared. The whole disposable force of Austria, for the defence of Silesia, amounted to 3000 men. The invading army amounted to 28,000. Breslau the capital, Glogau the principal fortress, every town, speedily fell before him. In a note to his friend Jordan, who had attempted to dissuade him from the enterprise, he wrote, in a mixture of scoffing and exultation--