It seems as if the Hereditary Grand Duke is trying to cover as many European countries as possible during the last couple of days. After visiting Liechtenstein with Princess Alexandra to support the Luxembourgish athletes at the 14th Games of the Small States of Europe, it was now time for Guillaume to pay a visit to Italy.
Originally the Grand Duke was scheduled to attend the festivities to celebrate the 150th anniversary of the unification of Italy under King Vittorio Emanuele II, but Guillaume took his father's place and made his way to Rome to be part of the Luxembourgish delegation. About 80 representative of different states attended the military parade held in the Via dei Fori Imperiali, among them the Hereditary Grand Duke seated together with the Crown Prince of Norway and the Hereditary Prince of Liechtenstein.
Photos of the festivities can be found at Daylife. Or just click here, here, here and here to see the pictures showing Guillaume.
Sources: Tageblatt, Daylife, Wort