Austria's coastal ports, and played a significant role in transporting troops across the Danube as well as denying Turkish control over the strategically important river. Austria remained without a proper seagoing navy, however, even after the need for one became apparent with the French Navy bombardment of the port of Trieste during the War of Spanish Succession. Lacking any sea power, Austria was unable to protect its coastal cities or project power into the Adriatic or Mediterranean Seas. The war ended with the treaties of Utrecht, Rastatt, and Baden. Under the terms of the Treaty of Rastatt, Austria gained the Spanish Netherlands, the Kingdom of Naples, the Kingdom of Sicily, the Kingdom of Sardinia, and the Duchy of Milan. While Austria's control over Sardinia and Naples was cut short by their loss to Spain in 1734 during the War of Polish Succession, these territories as well as the new Austrian Netherlands gave Austria greater access to the sea than ever before. Following the War of Spanish Succession, Austria once again developed interest in establishing a proper navy in order to protect its now numerous coastal possessions. This coincided with the majority of European nations' growing interest in mercantilism, the founding and development of colonies, and the chartering of overseas trading companies during the early 18th century. Austria's largest obstacle in engaging in overseas trade and naval enterprises however lay in the country's geography. Despite Austria having a lengthy coastline along the Adriatic Sea, the major ports it possessed along its main coastline were isolated from Vienna by the large Austrian Alps. Furthermore, there were no major rivers linking Austria's Adriatic ports to the interior of the country. Austria also enjoyed three major navigable rivers which flowed through the country, the Elbe, the Oder, and the Danube. However, the Elbe and the Oder flowed through the Kingdom of Prussia before emptying into the North and Baltic Sea respectively, while the mouth of the Danube lay within the territory of the Ottoman Empire. Both of these nations remained major rivals of Austria throughout the 18th century, preventing the Austrians from using its major rivers to gain access to the sea. The Ostend Company Following the War of Spanish Succession, Austria's greatest outlet to the sea lay in the newly acquired Austrian Netherlands. While non-contiguous with the rest of Austria, the Austrian Netherlands lay within the boundaries of the Habsburg-dominated Holy Roman Empire.