Johann, Hans or Johannes Virdung of Hassfurt was a celebrated astrologer of the early sixteenth century from the Electoral Palatinate. He had an official position at Heidelberg, at the court of the Elector Palatine. He wrote various works under generic names (Prognosticon, Practica), including a millennarian work, Practica von dem Entchrist.
Virdung studied at the University of Leipzig beginning in 1481, then in Cracow from 1484 to 1486 or 1487. He returned to Leipzig in 1487, where he graduated as a "Magister" in 1491. It has been suggested that Virdung was of the school of the astronomer Albertus de Brudzewo, and had studied with him and Johannes de Glogovia in Cracow.
- Dates given as c.1465-c.1535..
- Around 1510, according to this PDF by Denis Crouzet. Published 1525, title page.
- An early work is the Prognosticon printed 1490. It was followed by others (1492, 1493, 1494, 1497 at least). (This PDF for details.)
- There is the 1584 Joannis Hasfurti medici ac astrologi praestantissimi, the title of which implies Virdung had a reputation as physician; he may not have contributed more than his name.
- 20 August 1507,  (German language). In connection with this,  describes Virdung as 'mathematician and court astrologer'.
- Steinmetz, "Johann Virdung von Hassfurt", in Astrologi hallucinati p. 197.
- By Kazimierz Piekarski
- Jan Glogowczyk, Jan Glogau, Jan of Glogow (1455-1507). See pl:Jan z Głogowa.
- Max Steinmetz (1986), "Johann Virdung von Hassfurt, sein Leben und seine astrologischen Flugschriften", in Astrologi hallucinati, stars at the end of the world in Luther's time
- Lynn Thorndike Johann Virdung of Hassfurt again Isis 25, 1936, p. 363; Faust and Johann Virdung of Hassfurt, Isis 26, 1936/37, p. 321; Another Virdung Manuscript, Isis 34, 1942/43, p. 291; Johann Virdung of Hassfurt: dates of birth and death, Isis 37, 1947, p. 74