By convention, the title of Holy Roman Emperor could only be recognized after coronation by the Pope of Rome. Since Constantine's conversion, this convention had become one of the legitimate procedures by which a Roman emperor gained recognition.
However, ever since Martin Luther posted the "Ninety-Five Theses" in 1517, some had begun to question this "convention."
One was the Dutch. In their early years, they had competed for a long time with Hanseatic League merchants in the Baltic Sea fishing and shipping trades. They had honed their naval skills amid the gales of the North Sea, and through their maritime advantage, they firmly controlled the grain trade along the Baltic coast, ensuring stable naval logistics, while launching indiscriminate raids on Habsburg dynasty merchant ships at sea.
The other was the Swedes. Gustav II had launched the Thirty Years' War, inflicting severe damage on the Holy Roman Empire. Yet after Gustav's death, a plan supposedly emerged: the Swedish crown prince would marry Brandenburg's heir. If it truly came to pass, the Hohenzollern family would no longer merely be kings of Prussia, but kings of a Swedish-German-Baltic kingdom.
The name Pomerania came from the Latin Longum mare, meaning "a country by the sea"; in Polish, it meant "coast." It had once been territory of the Holy Roman Empire. Later, East Pomerania was conquered by the Teutonic Knights and became part of Prussia, before later becoming part of the Kingdom of Poland.
During the Thirty Years' War, the Swedes occupied Pomerania. After the Northern War ended, France, Sweden, and Brandenburg negotiated and signed the "Peace of Westphalia." Sweden gained West Pomerania, while Prussia gained East Pomerania.
Yet the dispute between Brandenburg and Sweden still had not subsided, especially over West Pomerania. Rabastan Lestrange called it the Dunkirk of the north. This was not