"Belgian national day" . . "Anniversary of the date in 1831 thatKing Leopold Iswore allegiance to theconstitutionas the firstKing of the Belgians" . . . . . "National Day" . . . . . "21 July 1831" . "national holiday" . "Belgium" . . "Belgian National Day" . . . . . "the Belgian national holiday" . . . . . . . . . . . . . . "Belgian National Day" . . . . .