Gusev is a town and the administrative center of Gusevsky District of Kaliningrad Oblast, Russia, located at the confluence of the Pissa and Krasnaya Rivers, near the border with Poland and Lithuania, east of Chernyakhovsk. Population: 28,177 (2021 Census); 28,260 (2010 Russian census); 28,467 (2002 Census); 27,031 (1989 Soviet census).

The Salzburg Protestants were Protestant refugees who had lived in the Catholic Archbishopric of Salzburg until the 18th century. In a series of persecutions ending in 1731, over 20,000 Protestants were expelled from their homeland by the Prince-Archbishops. Their expulsion from Salzburg triggered protests from the Protestant states within the Holy Roman Empire and criticism across the rest of the Protestant world, and the King in Prussia offered to resettle them in his territory. The majority of the Salzburg Protestants accepted the Prussian offer and traveled the length of Germany to reach their new homes in Prussian Lithuania. The rest scattered to other Protestant states in Europe and the British colonies in America.