[3] From birth he had the lesser princely title and the nobiliary particle von Hohenberg accorded his mother as a predicate at the time of her marriage, and in 1905 he shared with his siblings her receipt of the style "Serene Highness".

[citation needed] Although Sophie had been raised from Princess (Fürstin) to Duchess (Herzogin) in 1909 by Emperor Franz Joseph, because that title was accorded ad personam, Maximilian did not inherit it upon her death in 1914.

[2] In 1919, following the defeat of the Austro-Hungarian Empire and collapse of the Habsburg monarchy, the new republic of Czechoslovakia expropriated Konopiště Castle, Maximilian's chief residence, and other family properties in the former Kingdom of Bohemia, and expelled the brothers to Austria.

Having spoken out for the independence of Austria and against the Anschluss, Maximilian and his brother were arrested by the Reich authorities and interned in Dachau concentration camp,[2] where they were chiefly employed in cleaning the latrines.

According to Leopold Figl (who served as Chancellor of Austria after World War II), they did so cheerfully and maintained comradely relations with fellow prisoners.