History of the Republic of Venice a powerful fleet sailed from Venice, to resolve the problem of the Narentine pirates. The fleet visited all the main Istrian and Dalmatian cities, whose citizen, exhausted by the wars between the Croatian king Svetislav and his brother Cresimir, swore an oath of fidelity to Venice. the Main Narentine harbours (Lagosta, Lissa and Curzola) tried to resist, but they were conquered and destroyed (see: battle of Lastovo). The Narentine pirates were suppressed permanently and disappeared. Dalmatia formally remained under Byzantine rule, but Orseolo became "Dux Dalmatie" (Duke of Dalmatia"), establishing the prominence of Venice over the Adriatic Sea. The "Marriage
Geology of the North Sea The sea level is to higher than present day levels. In northwestern Europe, chalk deposits from the Upper Cretaceous are characteristic for the Chalk Group, which forms the white cliffs of Dover on the south coast of England and similar cliffs on the French Normandian coast. The group is found in England, northern France, the low countries, northern Germany, Denmark and in the subsurface of the southern part of the North Sea. Stagnation of deep sea currents in middle Cretaceous times caused anoxic circumstances in the sea water. In many places around the world, dark anoxic shales were formed during