First, there was a war to be won and his country needed liberating. Before he saw action, however, his commanding officer was kind enough to call on his mother, the Grand Duchess Charlotte, who was in exile in London. She is said to have remarked: “Well if he gets killed that will be that, but please do not allow him to be taken prisoner.”
He landed in Normandy on June 23, 1944, and took part in Operation Goodwood, intended to clear the ground for the taking of the communications centre of Caen, which fell on July 20. He then advanced into Belgium, reaching Brussels on September 3.
General George Patton, commanding the US Third Army, was about to enter Luxembourg, but on hearing that the crown prince was near by, he arranged for him to take part. On September 10, 1944, “John Luxembourg” crossed into the country at Rodange, the spot where his family had fled the Nazi invasion more than four years earlier. He later joined Patton in the first Jeep to enter Luxembourg city.
Returning to his unit, he was involved in the Battle of the Bulge, the Reichswald attacks and, as German resistance crumbled, the move into Bremen and Hamburg. On April 14, 1945 he was back in Luxembourg with his father, Prince Félix, to greet the grand duchess as she returned from exile accompanied by Winston Churchill and to celebrate with a jubilant population.
And this is rather what Ampleforth is for:
His early education was in Luxembourg followed by studies at Ampleforth College in North Yorkshire, where he learnt to eat whatever was set before him, a skill that came in handy in the army and at state banquets.