Schleswig – Flag in Lexicon and Shop https://www.flaggenlexikon.de/fdtschlw_me.htm
Schleswig existed as a county between 1025 and 1474, as a duchy between 1474 and 1864, came to the Prussian province of Schleswig-Holstein in 1867, and to the state of Schleswig-Holstein in 1946. Its flag – which can also be ordered on these pages – showed the colors blue and yellow.
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