When Selvo approached the city, Guiscard's ships had already anchored in the harbor at Durazzo. Though the battle was fierce, superior tactics by the skilled Venetian fleet overpowered the inexperienced Normans who were mostly used to land battles. The battered fleet led by Guiscard retreated into the harbor after losing many ships. Victorious at sea, Selvo left the fleet under the command of his son and returned to Venice a hero. Because of the help given to the Byzantine Empire, the Republic of Venice was awarded a Golden Bull: a decree by Emperor Alexios I Komnenos granting Venice many privileges, including a tax exemption for Venetian merchants, that would be crucial for the future economic and political expansion of Venice in the eastern Mediterranean.