Gdańsk (Danzig), Poland's wealthiest city, faced difficulties due to ongoing conflict on the sea and piracy. The capital, Kraków, was also affected as the trade route from the Baltic ran through Gdańsk and along the Vistula River to the southern province of Lesser Poland. Gdańsk, which was privileged with its own army and government, resisted against Sigismund's order of sending privateers and creating the first Polish Admiralty in their city. Most of the deputies in the city council were merchants and tradesmen of German descent or Protestants who were either politically leaning towards Sweden or fighting for the status of an independent 'city state'. 11 Polish privateers sent by Sigismund were eventually executed, which greatly angered the king. Poland then joined Denmark against Sweden for Baltic domination. The war ended as status quo ante bellum in 1570 with the Treaty of Stettin, which was signed by Bishop Martin Kromer on behalf of Sigismund. However, the ineffective conflict did have its input in establishing Poland's first registered naval fleet (Naval Commission) in 1568. Union of Lublin Sigismund's most striking legacy may have been the Union of Lublin, which united Poland and Lithuania into one state, the Polish–Lithuanian Commonwealth, jointly with German-speaking Royal Prussia and Prussian cities. This achievement might well have been impossible without the monarch's personal approach to politics and ability to mediate. At first, the treaty was perceived as a threat to Lithuanian sovereignty. Lithuanian magnates were afraid of losing their powers, since the proposed union would lower their rank and status to an equivalent with petty nobility rather than wealthier Polish aristocracy. On the other hand, the unification would provide a strong alliance against Russian (Muscovite) attack from the east. Lithuania was ravaged by the Muscovite-Lithuanian Wars which endured for over 150 years. During the Second War, Lithuania lost of its territory to Russia, and the final defeat in the Livonian War would result in the country's incorporation into the Russian Tsardom. Furthermore, the Poles were reluctant to aid Lithuania without a quid pro quo. The most vocal opponent of the union was Sigismund's brother-in-law, Mikołaj "the Red" Radziwiłł (), who viewed the agreement as "peaceful annexation of Lithuania" by Poland. He also resisted polonisation policies which forced ethnic Lithuanians to change their names and native language to Polish or Latin. As another war with Russia loomed, Sigismund Augustus pressed the members of parliament (Sejm) for the union,