In 1917, Emperor Charles of Austria granted Francis Ferdinand and Sophie's eldest son the title of "Duke" with the style of Highness, the other members of the family remaining titled "Prince" or "Princess" with the lesser style of Serene Highness.
Emperor Charles of Austria granted Francis Ferdinand and Sophie's eldest son the title of "Duke" with the style of Highness, the other members of the family remaining titled "Prince" or "Princess" with the lesser style of Serene Highness. This was in 1917.