Despite the relative peace of the early years of Selvo's reign, the forces that would eventually lead to his deposition had already swung into action. In southern Italy, the Duke of Apulia and Calabria, Robert Guiscard, had spent the majority of his reign consolidating Norman power along the heel and toe of "lo Stivale" by expelling the Byzantine armies. Guiscard was pushing north toward the Papal States (to which the Duchy of Apulia and Calabria was allied), and was threatening Byzantine control of cities along the Ionian and Adriatic seas. In May 1081, Guiscard led his army and navy across the sea to lay siege to the port city of Durazzo, as it was one end of the famous Via Egnatia, a direct route to the Byzantine capital of Constantinople. Alexios I Komnenos, the newly crowned Byzantine Emperor, dispatched an urgent message to Selvo asking for the mobilization of the Venetian fleet in defense of Durazzo in return for great rewards. The Doge wasted no time in setting sail for the besieged city in charge of his fleet of 14 warships and 45 other vessels. Selvo was motivated not only by his familial ties and the promise of reward, but also the realization that Norman control over the Strait of Otranto would be just as great of a threat to Venetian power in the region as it would be to their ally in the east.