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 Bothnia of Bothnia into a southern gulf and northern lake across the Norra Kvarken area in about 2,000 years. Some historians suggest that the adventurer Ottar was referring to the Gulf of Bothnia when he spoke of the "Kven Sea" in the 9th century. It is also possible that Claudius Clavus's usage of the term "Mare Gotticus" in the 15th century refers to the Gulf of Bothnia. The land surrounding the Gulf of Bothnia is heavily forested. Trees are logged, then transported to the coast for milling. The gulf is also important for oil transport to the coastal cities and ore