The two principalities were once again united under the younger son, Frederick, after John's death on 11 June 1420. At the Council of Constance in 1415, Emperor Sigismund vested Frederick with the hereditary title of an Elector of Brandenburg (as Frederick I). Frederick finally sold his burgravial title to the citizens of the Imperial City of Nuremberg. On his death in 1440, his territories were again divided between his sons: the eldest, John the Alchemist had waived his right of primogeniture and succeeded his father in Kulmbach-Bayreuth, while the second, Frederick Irontooth, received the Brandenburg electorate. Ansbach passed to the third son Albert Achilles.