 The Gesta Hungarorum says that Árpád took " an oath of the leading men and warriors of Hungary , " and " had his son , Prince Zoltán elevated " to prince in his life . However , the reliability of this report and the list of the grand princes in the Gesta Hungarorum is dubious . For instance , it ignores Fajsz , who ruled when Constantine VII Porphyrogenitus was completing his De Administrando Imperio around 950 . 
