Hanseatic League – Flag in Lexicon and Shop https://www.flaggenlexikon.de/fhanse_me.htm
From the 12th to the 17th century, the Hanseatic League was a league of cities under the leadership of the city of Lübeck. The colors of the Hanseatic League on flags, banners and pennants were white and red.
the Lower Rhine to Livonia and from Stockholm to Krakau