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
History of the Republic of Venice signed a treaty of peace by which the Turks took the Aegean duchy of Naxos from the Sanudo family. After Preveza the supremacy of the sea passed to the Ottomans. Difficulties in the rule of the sea brought further changes. Until 1545 the oarsmen in the galleys were free sailors enrolled on a wage. They were originally Venetians, but later Dalmatians, Cretans and Greeks joined in large numbers. Because of the difficulty in hiring sufficient crews, Venice had recourse to conscription, chaining the oarsmen to the benches as other navies had already done. Cristoforo da Canal was the first Venetian