Unnamed German Kaiser

The "kaiser" whom the German aviator refers to without naming in "Ad Astra" is Kaiser Wilhelm II (Friedrich Wilhelm Victor Albert von Hohenzollern); he ruled Germany as emperor from June 1888 to November 9, 1918. On that date, having lost the support of the army, he abdicated, and fled the country a day later. The German prisoner says he does not serve "baron and kaiser" (418), but he is proud when his brother Franz is declared "ace iron cross by the kaiser's own hand" (419).