The Gesta Hungarorum names "Wazul et Zar Ladislaum" as the sons of "Mihal…frater Geichæ". The Chronicon Varadiense names "ducem…Vazul et ducem Ladislaum calvum" as the two sons of "Michael dux". The Kronika Wegiersko-Polska names "Stephanum, Mychl et Vanzul" as the three sons of "Geyza", adding that "Vanzul" was killed by "effosionem oculorem" by "reginam Gesla, consortem regis sancti Stephani".
Duke between March and Gran. Representing the more conservative, traditional element of Hungarian society, he rebelled against King István I and his Catholic pro-western policies. The Gesta Hungarorum records that, after the death of his son Imre, "rege Stephano" sent messengers to bring "Wazul filium sui patruelis" from his prison at "Nistriæ" to have him declared successor to the kingdom but that "Kysla regina" sent "comitem Sebus" to blind Vazúl and have moulten lead poured into his ears, after which Vazúl fled to Bohemia from where he was brought back to Hungary. Bak dates this event to 1037, although this appears late if the events happened soon after Imre's death in 1031. 1