While Austria had a port with the incorporation of Trieste, the city was granted a large degree of autonomy and successive Dukes of Austria paid little attention to the port or the idea of deploying a navy to protect it. Until the end of the 18th century, there were only limited attempts to establish an Austrian navy. During the Thirty Years War, Generalissimo Albrecht von Wallenstein was awarded the Duchies of Mecklenburg-Schwerin and Mecklenburg-Güstrow as well as given the title "Admiral of the North and Baltic Seas" by Holy Roman Emperor Ferdinand II in 1628 after scoring several military victories against Denmark–Norway in northern Germany. However, Wallenstein failed to capture Stralsund, which resisted the Capitulation of Franzburg and the subsequent siege with assistance of Danish, Scottish and Swedish troops, a blow that denied him access to the Baltic and the chance of challenging the naval power of the Scandinavian kingdoms and of the Netherlands. Wallenstein's assassination at the hands of his own officers in 1634 prevented the development of any Austrian navy in either the North or Baltic Seas.