King of Germany (1440–93), Holy Roman Emperor (1452–93). He inherited the Habsburg domains as Archduke of Austria in 1424. He failed to assert family interest in Hungary, and was troubled by rival claimants to his own lands, and by Turkish attacks, which became more threatening after the fall of Constantinople in 1453. On good terms with the papacy, he was the last Holy Roman Emperor to be crowned by the pope at Rome. He earned unpopularity by his efforts to suppress John Huss’s followers in Bohemia and Hungary. By arranging the marriage of his son Maximilian I to Mary, daughter of Charles the Bold, he greatly extended the dynastic power of the Habsburgs.