Johannes Schallermann, who later became a lawyer, was born around 1373.
FSchallermann studied in Heidelberg and Padua and finally enrolled at the University of Vienna, where he also taught canon law. He was dean of the faculty of law three times and in the summer semester of 1416 he was elected rector of the university. In 1420 he was a provincial superintendent.
From the 1420s Schallermann became increasingly involved in Habsburg church politics, which is why he resigned his professorship around 1425. He acted as councillor to Duke Frederick IV of Tyrol and court chaplain to King Sigismund, and held various benefices and offices: in 1428 he became parish priest of the well-funded parish of Krems, and from 1431 to 1432 he appears as cathedral scholaster and cathedral provost of Brixen. He is also mentioned as auditor of the papal rota from 1423 to 1432. In 1433 he was appointed Bishop of Gurk. In addition to his episcopal duties, Schallermann was also vicar general of the archdiocese of Salzburg.