"Archduke Joseph Ferdinand of Austria (24 May 1872 – 28 August 1942) was an Austro-Hungarian Archduke and the titular Grand Duke of Tuscany from 17 January 1908 to 2 May 1921, military commander, from 1916 Generaloberst, and early advocate of air power. He later retired to life as a common citizen of Austria, and was briefly imprisoned in Dachau during the Nazi era." - (en.wikipedia.org 29.01.2020)