By 1440, Vienna became the main resident city of the Habsburg Dynasties and the capital of the Holy Roman Empire (1452) as well as the cultural centre for arts and science, music and fine cuisine. The economic mainstays were trade and wine export. Wine production was protected by import bans on foreign, particularly Hungarian, wines. Political unrest ending with the Hungarian occupation of Vienna under King Matthias I Corvinus (1485 - 1490). Vienna's economy was affected drastically. The "Stapelrecht," became ineffective. So, the Habsburgs turned to financial prowess of powerful trade dynasties such as the Fuggers. This time also marked the end of late medieval burgher autonomy of Vienna as it was now the center of a vast empire.
During this time, a mystery was left behind that can be seen on the doorways of castles and cathedrals built in the reign of Frederick III (1440-1499). The vowels AEIOU are carved over archways and portals; however; the cipher was never spelled out. All those who knew are long deceased. Some have mistakenly claimed various explanations in German and Latin, including the “Austrian birthmark,” “Austria will survive all others on earth.” Most of this conjecture has proved to be anachronistic and almost as cryptic as the vowels themselves. Perhaps the sovereign simply enjoyed the Latin vowels.
