The Princess Royal was in Belgium on Saturday to attend the Last Post ceremony at the Commonwealth War Graves Commission of the Ypres Memorial at the Menenpoort (Menin Gate) as part of the Armistice Day commemorations marking 99 years since the end of WWI. For this event, Princess Anne repeated her black percher hat with large round button base and wrap-around feather trim.
Also on Saturday, Princess Astrid of Belgium represented her brother at the annual homage to the Unknown Soldier at the Congress Column in Brussels to commemorate victims of the two World Wars and peace operations and humanitarian operations abroad since 1945. For this ceremony, she wore military uniform complete with curled brim cap.
Photos from Getty and social media as indicated