Through his military alliance with the Byzantine Empire, Emperor Alexios I Komnenos awarded Venice economic favors with the declaration of a golden bull that would allow for the development of the republic's international trade over the next few centuries.

[2] However, in 991, Pietro II Orseolo became the Doge and spent his reign pushing the boundaries of the Republic further east down the western coast of the Balkan Peninsula with his conquests in Dalmatia in 1000.

Details of his family origins and even the year of his birth are unknown, but it can be assumed that he was a Venetian noble because, with the rare exception of Domenico Flabanico, only members of this class were elected to the position of Doge at this point in the Republic's history.

[9] He had also apparently been an ambassador to Holy Roman Emperor Henry III and he was certainly ducal counselor to Domenico Contarini prior to his election as Doge.

[9] Selvo is notable for being the first Doge in the history of Venice whose election was recorded by an eyewitness, a parish priest of the church of San Michele Archangelo by the name of Domenico Tino.

[13] According to Tino's account, on the day of the election, Selvo was attending mass for the funeral of the late Doge at the new monastery church of San Nicolò built under Domenico Contarini on Lido, an island in the Venetian Lagoon.

The location was ideal for the funeral of a Doge not only because St Mark's Basilica was under construction at the time, but the new church was also spacious enough to hold a fairly large number of people.

[15] After the bishop of Venice asked "who would be worthy of his nation," the crowds chanted, "Domenicum Silvium volumus et laudamus" (We want Domenico Selvo and we praise him).

[15][17] Barefoot, in accordance with tradition, Selvo was led into St Mark's Basilica where, amidst the construction materials and scaffolding, he prayed to God, received his staff of office, heard the oaths of fidelity from his subjects, and was legally sworn in as the 31st Doge of Venice.

[15][20] In the east, Selvo not only maintained good trade relations with the Byzantine Empire, but also married into their royal family to consolidate the alliance that had existed for many years between the two nations.

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.

[23] 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.

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.

Meanwhile, Guiscard advanced rapidly across the Balkan Peninsula, but his march was halted by an urgent dispatch and a call for help from his greatest ally, Pope Gregory VII.

Guiscard responded by returning to Italy and marching on Rome to temporarily expel Henry IV, but in the process, he lost almost all the territories he had gained in the Balkans.

His strategy, though perhaps risky, was ultimately well-calculated as it caused mass confusion among the Venetians, who were overwhelmed on all flanks, while the Greeks fled what they assumed to be a losing battle.

[32]After Selvo was deposed, it took several years for Venice to recover from the defeat at Corfu and for the Venetians to fully realize the immediate impact of his actions as Doge.

[33] This final and most famous version of the church, whose construction was begun by Domenico Contarini and finished by Vitale Faliero in 1094, remains an important symbol of the long periods of medieval Venetian wealth and power.

Though Selvo did not oversee the beginning or completion of St Mark's Basilica, his rule covered a longer period of its construction than the other two Doges who oversaw the project.