Maurice was the son of Henry, and succeeded his father in the government of that part of Saxony which belonged to the Albertine line. "This young prince, then only in his twentieth year, had, even at that early period, begun to discover the great talents which qualified him for acting such a distinguished part in the affairs of Germany. As soon as he entered upon the administration, he struck out into such a new and singular path, as showed that he aimed from the beginning at something great and uncommon." He professed to be a zealous Protestant, but objected to join the league of Smalcald under the pretense that its principles were not sufficiently scriptural. He avowed his determination to maintain the purity of religion, but not to entangle himself in the political interests, or combinations to which it had given rise. Such was the consummate duplicity and the Satanic policy of this young man. At this very time, with great political sagacity, he was weighing both sides, and foreseeing that the Emperor was most likely to prevail in the end, he affected to place in him the most unbounded confidence, and to court his favor by every possible means, and also the favor of his brother, Ferdinand.
At the Diet of Ratisbon, in the month of May 1546, Maurice concluded a treaty with the Emperor, in which he engaged to assist him as a faithful subject, and Charles, in return, stipulated to bestow on him all the spoils of the Elector, his dignities as well as his territories. But so little did the Elector suspect treachery in his young relative and neighbor, who had received many kindnesses from him, that, on leaving to join the confederates, he committed his dominions to the protection of that prince; and he, with an artful appearance of friendship, undertook the charge. The whole plan being now completed, the Emperor sent Maurice a copy of the imperial ban denounced against the Elector and the Landgrave, requiring him, upon the allegiance and duty which he owed to the head of the empire, instantly to seize and retain in his hands the forfeited estates of the Elector.
This artifice, which made the invasion appear to be one of necessity rather than of choice, was but a thin veil to conceal the treachery of both. After some formalities were observed, to give a specious appearance to his reluctance, Maurice marched into his kinsman's territories, and, with the assistance of Ferdinand, attacked and defeated the Elector's troops, and took all things under his own administration.