Nicolaus von Tüngen came from a Teutonic Prussian burgher family in Tüngen (Bogatyńskie) near Wormditt (Orneta) in Ermland (Warmia). He worked in the Roman Curia for many years as a secretary, and accumulated many church offices, including in 1459 becoming Canon of Breslau (Wrocław) and Canon of Warmia. After the death of Warmia's Bishop Paul von Legendorf, Tüngen was chosen as his successor by the Warmia diocese chapter on 10 August 1467. Tüngen received the pope's agreement for his nomination on 4 November 1468 and obtained the bishop's insignia in Rome.