The eldest of Tancred of Hauteville's twelve sons, William and Drogo, were the first to arrive in the south sometime around 1035. They so distinguished themselves against the Greeks that William was inaugurated as count of Apulia and Calabria and lord of Ascoli, Drogo as lord of Venosa. In 1047, Drogo was confirmed by the Emperor Henry III as William's heir and a direct vassal of the imperial crown. Their next brother, Humphrey, succeeded Drogo and defeated Pope Leo IX at the Battle of Civitate, making the Hauteville power the highest in the region. He was in turn succeeded by a fourth brother, the first by Tancred's second wife, Robert Guiscard.