Butler's maquette was the winning entry in the international competition for a monument to 'The Unknown Political Prisoner'. After his original maquette was severely damaged, Butler made two replicas. This work was made between 1955 and 1956 and represents Butler's vision of a monument to 'The Unknown Political Prisoner' in its most fully developed form. Four times larger than the maquettes, it was welded from pieces of steel forged by the artist. It includes details such as the ladder-like structure which climbs one of the legs of the tower. Several leading Germans, including the mayor of Berlin were keen to see the monument built in West Berlin, although this ambition was never realised.