Royal Prussia Flag

The flag of Royal Prussia. Between 1466 and 1772 the territory of Prussia formed a province of the Kingdom of Poland, the informal name of Prussia was real, as distinct from Prussia Ducal Prussia, which was part of the Duchy of Prussia. The royal flag of Prussia, issued in 1466 by the Polish king Casimir IV Jagiello, was a white cloth coat of arms charged in the province: a black eagle with golden beak and claws and a golden crown around the open neck.