1440: Emperor Frederick and the Bohemian Heritage
Friedrich III (1415–1493), who became Duke of Styria, Carinthia, and Carniola in 1424 and Duke of Austria in 1439, was elected King of the Romans in Aix-la-Chapelle in 1440 and crowned Holy Roman Emperor by the pope in 1452. His motto, "AEIOU", for which a number of different interpretations exist, became widely known, one of its most popular readings being "Austriae est imperare orbi universo."
Emperor Frederick III’s book collection can be said to have formed the core holdings of the imperial court library. He had 110 outstandingly valuable books brought to his castle at Wiener Neustadt, including the Bohemian heritage, which comprised the handwritten treasures of King Wenceslas I (1361–1419) from Prague. One of the most precious objects was certainly the Wenceslas Bible, a German Bible translation made well before Luther, which, although incomplete, consists of 2,400 two-column pages featuring more than 600 miniatures and magnificent marginal decoration.
Another precious book from his holdings is the Golden Bull, a copy of the decree on the election of the King of the Romans passed by the Luxembourgian Emperor Charles IV (1316–1378) in 1356. When the German prince electors replaced King Wenceslas I in 1400, the latter, protesting against his deposition, had the Golden Bull, according to which he had legitimately been elected King of the Romans, transcribed and adorned with superb images. Emperor Frederick III, who took over the heritage, had a new cover made, which was inscribed with his motto, "AEIOU".