File:Alsace-Lorraine Germany Flag 1871–1918.png

Summary
Historic Arms, not used by state institutions. The following Licensing applies

The copyright holder of this file, David Liuzzo, allows anyone to use it for any purpose, provided that the copyright holder is properly attributed. Redistribution, derivative work, commercial use, and all other use is permitted. Attribution: David Liuzzo

From https://en.wikipedia.org/wiki/Alsace-Lorraine#/media/File:Dienstflagge_Elsa%C3%9F-Lothringen_Kaiserreich.svg