b. Innsbruck (Tyrol), Sept. 21, 1415, d. Linz (Upper Austria), Aug. 19, 1493, Emperor (as King F. IV, as Duke F. V). Son of Duke Ernst the Iron, one of the Styrian line of the Habsburgs, whom he succeeded in Styria and in Carinthia in 1424. In 1439 became guardian of the minor Sigmund of Tyrol (until 1446) and took over guardianship of Ladislaus Postumus in Austria in 1440. In 1452 the estates forced him to release Ladislaus from tutelage. After Ladislaus's death in 1457 F. came into conflict with his brother Albrecht VI over the succession to the throne and was besieged together with his family in his Vienna residence in the Castle of Vienna in 1462. After Albrecht's death in 1463 was also recognized as Duke of Austria. When the claims of the Privilegium maius (a forged charter commissioned by Duke Rudolf IV, by means of which he claimed privileges for Austria) were asserted in 1453, F. legalized the title of Archduke. He became German King in 1440, was crowned Emperor in Rome in 1452, and King of Hungary in 1459. From 1452 was married to Eleonore of Portugal, with whom he had a son, Maximilian I. F. welcomed the fact that his son was elected Roman King in 1486, but their relationship was often marked by tensions. Around 1470 came into conflict with Matthias Corvinus of Hungary, who occupied parts of Lower Austria from 1482. F. enlarged his residences in Graz, Wiener Neustadt and Linz, and some of his buildings are marked with his personal insignia AEIOU, the meaning of which is not fully clear since there are various ways in which the abbreviation may be interpreted. F. established the dioceses of Laibach/Ljubljana (1462), Vienna and Wiener Neustadt (both in 1469) and brought about the canonization of Margrave Leopold III in 1485. A pious man, he loved neither warfare nor hunting, but was very interested in botany, alchemy and astrology. He was ambitious and determined, tough and tenacious, economical and dignified. In part, he owed his success to the fact that he survived his adversaries. He is buried in St Stephen's Cathedral in Vienna.
Literature#F. III., exhibition catalogue, Wr. Neustadt 1966; B. Rill, Ks. F. III., 1987.