Despite the loss of his throne, Duke Robert and his family enjoyed considerable wealth, travelling in a private train of more than a dozen cars among his castles at Schwarzau am Steinfeld near Vienna, Villa Pianore [it] in northwest Italy, and the magnificent Château de Chambord in France.

[citation needed] Less than four months after Robert's death in 1907 the Grand Marshal of the Austrian Court declared six of the children of his first marriage legally incompetent, at the behest of Duchess Maria Antonia.

[citation needed] During the Battle of Caporetto, Prince Félix accompanied his brother-in-law Charles I of Austria, who had been visiting troops on the Italian front, on a return journey to Trieste.

Urban legend has it that Félix lost the Grünewald, a forest owned by the Grand Duchess, at a casino in 1934, but this is false; part of the property was sold, along with Berg Castle, to the Luxembourgian government, with the revenue paying for the upkeep of the grand-ducal household, and was not spent on personal consumption, let alone gambling losses.

[5] During World War II the grand ducal family left Luxembourg shortly before the arrival of Nazi troops, settling in France until the capitulation, in June 1940.

Subsequently, the family and the Grand Duchess' ministers received transit visas to Portugal from the Portuguese consul Aristides de Sousa Mendes, in June 1940.

After travelling through Coimbra and Lisbon, the family first stayed in Cascais, in Casa de Santa Maria, owned by Manuel Espírito Santo, who was then the honorary consul for Luxembourg in Portugal.

The line can be traced back more than 1,200 years from Robert of Hesbaye to the present day, through Kings of France & Navarre, Spain and Two-Sicilies, Dukes of Parma and Grand-Dukes of Luxembourg, Princes of Orléans and Emperors of Brazil.