In this interview, Guy de Muyser, diplomat in the Luxembourg Foreign Ministry from 1956 to 1969 and from 1980 to 1991, looks back on the negotiations associated with the seat of the Court of Justice of the European Communities in Luxembourg and the constant involvement of Pierre Werner, Minister of State and President of the Luxembourg Government from 1959 to 1974 and from 1979 to 1984, to make Luxembourg a permanent seat of the European institutions.