Generalfeldmarschall August von Mackensen, officer in the German Army, wearing the Totenkopf (skull and cross bones) which was part of German military gear since the 18th century
Anton Ludwig August von Mackensen (6 December 1849 – 8 November 1945), born August Mackensen, was a German soldier and field marshal. He commanded with success during the First World War and became one of the German Empire’s most prominent military leaders. After the Armistice, Mackensen was interned for a year. He retired from the army in 1920 and was made a Prussian state councillor in 1933 by Hermann Göring. During the Nazi era, Mackensen remained a committed monarchist and sometimes appeared at official functions in his First World War uniform. He was suspected of disloyalty to the Third Reich, although nothing was proved against him at this time.
I’ve always found it a nice detail how he continued to show up in his old imperial Prussian officers uniform long after the empire had fallen. (Prussia was one of several states that unified and became Germany in the late 1800s. Before that there was no one country called Germany, it was Prussia, Bavaria, etc.)
Here he is at the funeral of Wilhelm II in 1941: