He was the illegitimate son of King Johann of Bohemia. His mother’s name is not passed on. On August 2, 1342, Pope Clemens VI proclaimed him provost of the Diocese Prague, following King Johann’s wish. On July 20 of the same year, pope Nicolaus had granted him canonicate and benefices of Vyšehrad. In 1345, he personally delivered a message of King Johann of Bohemia to Clemens VI. In a document from 1348 Nicolaus calls himself dean of the church of Olmütz and royal chancellor.
Clemens VI appointed Nicolaus bishop of Naumburg on January 7, 1349, as one of the opponents to Johann of Miltitz. Nicolaus could not stand his ground; possibly he was only nominated and has never taken up office.
On October 31, 1350, Nicolaus informed the inhabitants of the city of Udine that he was the new patriarch. The appointment had taken place short before that. In May 1351, Nicolaus arrived in the Patriarchate of Aquileia and was solemnly received. During his term of office, he planned to found a commercial centre called "Carola" together with his half-brother, the future emperor Karl IV. This project was not to be realised.
In the end of 1351 and beginning of 1352, some noblemen were executed by order of the new patriarch. The men were said to have participated in the murder of the patriarch’s predecessor, Bertrand de St. Geniès.
In 1353, Karl IV consented to the erection of a studium generale for the City of Cividale. In October 1354, he visited the Patriarchate of Aquileia on his way to Rome. During his stay, Nicolaus presented a much sought-after relic, two pages of St. Marc’s gospel, to Karl. Nicolaus accompanied his half-brother on his way through Italy.
Karl IV conferred three duties to Nicolaus: Vicar for Trieste in 1354, Vicar of Tuscany in May 1355 and shortly afterwards General Vicar of Feltre and Belluno. On July 30, 1358 Patriarch Nicolaus died in Belluno. The cause is unknown – it is assumed, by sickness. Nicolaus is buried in Udine underneath the main altar of the church.
- Bianchi, G., Documenti per la storia del Friuli dal 1200 al 1400
- Guerra, Otium Foriiulii. Manoscritti, Museo Archeologico, Cividale
- Chronicon Spilimberghense
- Tirelli, R., I patriarchi. La spada e la croce XV secoli di storia, Pordenone 2000