Not an too easy question you raise, but we discussed it recently on a German forum so it should work: the Prussian Krieger-Verdienstmedaille was instituted in 1835 to be awarded to foreign soldiers for merit in war and peace time. Most awards in that early days went to Russians. In 1873 the style changed to what we see above. It was awarded on the white and black ribbon for soldiers who did not yet participate a war and on the black and white ribbon for those who won it in war or participated an earlier "Feldzug" before!. The awards in WWI, mainly to Austrians but as well to Ottoman and Bulga