King <a href="https://en.wikipedia.org/wiki/Constantine_I_of_Greece" class="extiw" title="en:Constantine I of Greece">Constantine I of Greece</a> as Crown Prince, in the field uniform of a Lieutenant General of the Hellenic Army, 1890s.
Bain News Service
<a rel="nofollow" class="external text" href="https://www.loc.gov/pictures/item/ggb2004007772/">Library of Congress</a>, cropped