Such was the condition and extent of Brandenburg in 1411 when Frederick of Hohenzollern became the representative of King Sigismund therein. Entering the electorate with a strong force in June 1412, his authority was quickly recognized in the middle mark, but the nobles of the old mark and of Priegnitz refused to follow this example. The two succeeding years were skilfully used by Frederick to make peace with the neighbouring princes, and having thus isolated his domestic enemies, he turned his arms against them early in 1414. Their strongholds were stormed, and in a few weeks their leaders were either prisoners or fugitives. A general peace was then declared at Tangermünde which enabled Frederick to leave the mark to the rule of his wife, Elizabeth, and to turn his attention elsewhere. Returning to Brandenburg as elector in 1416, the last flickers of the insurrection were extinguished; and when Frederick was invested at Constance in April 1417 his authority over the mark was undisputed. His next difficulty was with Pomerania, which had been nominally under the suzerainty of Brandenburg since 1181. The revival of this claim by the elector provoked an invasion of the mark by an army of Pomeranians with their allies in 1420, when Frederick inflicted a severe defeat upon them at Angermünde; but in 1424 a temporary coolness between the elector and the emperor Sigismund led to a renewal of the attack which Frederick was unable to repulse. This reverse, together with the pressure of other business, induced him to leave Brandenburg in January 1426, after handing over its government to his eldest son, John. John, called the "Alchemist," who was born in 1403, had been disappointed in his hope of obtaining the vacant electoral duchy of Saxe-Wittenberg in 1423. Lacking the diplomatic and military qualities of his father, his difficulties were augmented by the poverty of the country, and the evils which Frederick had suppressed quickly returned. The feeling of security vanished, the towns banded themselves together for defensive purposes, the rights of the margrave were again pledged to provide money, and in 1432 the land was ravaged by the Hussites. John never attained to the electoral dignity; for, in 1437, his father in arranging a division of his territories decided that Brandenburg should pass to his second and fourth sons, both of whom were named Frederick. The elder of the two took up the government at once, whereupon John left the mark for South Germany, where he remained until his death in 1464.