A.E.I.O.U.

[1] Frederick habitually signed buildings such as Santa Maria dell'Anima in Rome,[2] Burg Wiener Neustadt, or Graz Cathedral as well as his tableware and other objects with the vowel graphemes.

[5] Contemporary research has shown that the Roman chancellery of Frederick III used the interpretation En amor electis iniustis ordinor ultor.

It was also supposed that the Austriae est imperare variants probably go back to Frederick's proto-notary Heinrich Leubing.

[1][7][8] This verse was probably adopted by Frederick from a poem by Nicolaus Petschacher of Znaim who worked as a court official in the 1440s.

Many Latin and German interpretations have been attempted over the centuries; most of these versions refer to a motto of present-day Austria or the extensive Habsburg monarchy.

Illumination from the records of King Frederick, dated 1446
Heraldic plaque dated to 1466 with Habsburg motto F.I. A.E.I.O.U. Left part is Habsburg fesse coat of arms and right part is Counts of Celje coat of arms, united under Imperial double-headed eagle
A.E.I.O.U. monogram of Frederick III
Sundial in Meran (now Italy ) featuring an A.E.I.O.U. inscription