nicholas was an illegitimate descendant of the kőszegi family, according to a letter of pope clement v. his parentage is uncertain; initially, 19th-century historian antal pór considered he was the son of ivan kőszegi, then modified his standpoint and claimed his father was gregory, ivan's son. genealogist pál engel placed his name on the family tree as the son of ivan's brother, another powerful oligarch henry kőszegi, but without explanation and reference. excluding gregory due to estimate age, nicholas' biographer ádám vajk argued his diocese laid in the territory of ivan kőszegi, who ruled western transdanubia at the turn of the 13th and 14th centuries. accordingly, nicholas was a half-brother of gregory and john the wolf, ancestor of the bernstein family.