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
Gulf of Aden Gulf of Aden The Gulf of Aden, also known as the Gulf of Berbera, (, , ) is a gulf amidst Yemen to the north, the Arabian Sea and Guardafui Channel to the east, Somalia to the south, and Djibouti to the west. In the northwest, it connects with the Red Sea through the Bab-el-Mandeb strait, and in the southeast, it connects with the Indian Ocean through the Guardafui Channel. It shares its name with the port city of Aden in Yemen, which forms the northern shore of the gulf. Historically, the Gulf of Aden was known as "The Gulf