History of the Republic of Venice of the Sea" ceremony was established in this period. Orseolo died in 1008. Venice's control over the Adriatic was strengthened by an expedition by Pietro's son Ottone in 1017, by which time Venice had assumed a key role in balancing power between the Byzantine and Holy Roman Empires. During the long Investiture Controversy, an 11th-century dispute between Henry IV, Holy Roman Emperor and Pope Gregory VII over who would control appointments of church officials, Venice remained neutral, and this caused some attrition of support from the Popes. Doge Domenico Selvo intervened in the war between the Normans of Apulia and
Captain of the Gulf appointment of a Captain of the Gulf and the galley captains ("sopracomiti") for the galleys to be outfitted in Venice. The commanders of the galleys equipped by Venetian colonies were decided by the local colonists. In the 16th century, the Captain of the Gulf, at the head of a squadron that in peacetime numbered 7 to 12 galleys, patrolled the seas around the Venetian Ionian Islands. In wartime, the Great Council authorized the creation of a fleet under the Captain-General of the Sea, who led the fleet on overseas campaigns, e.g. in the Aegean Sea or the Levant; the Captain