Early in the 15th century, the Teutonic Order, a German military religious order founded during the Third Crusade, sought to expand its influence over Lithuania and Poland. Though its purported mission was to spread Christianity, it invaded the already Christian nations and was defeated at the Battle of Grunwald. Afterward, the Order's strength waned, and today it exists only as a clerical organization. How was the memory of the Battle of Grunwald used as propaganda during World War I?