According to Anonymous, Zoltán was born after 903, during his father's second campaign against Menumorut. The latter was one of the many local rulers who are solely mentioned in the "Gesta Hungarorum" among the opponents of the Hungarians during their conquest of the Carpathian Basin. In the "Gesta Hungarorum"'s narration, Menumorut was forced to surrender and to give his daughter in marriage to Zoltán in 904 or 905. When Menumorut died, Zoltán inherited his father-in-law's duchy east of the river Tisza, which Anonymous claims was inhabited by "the peoples that are called Kozár". Anonymous also states that Zoltán, still a minor, succeeded his father who died around 907. Zoltán, in turn, later abdicated in favour of his son Taksony and died "in the third year of his son's reign".