The Twelfth International Penal and Penitentiary Congress met at The Hague onAugust 14, 1950. The last such Congress had been held in Berlin in 1935. The Twelfth Congress dealt with such matters as the problems encountered in the application of penal law, the problem of a code of penal execution, and measures which might be substituted for the penal sentence in order to take into account the needs of a humane defense of society. The International Penal and Penitentiary Commission1 held meetings immediately preceding and following the congress on the question of its relationship with the United Nations. The prevention of crime and the treatment of offenders — which had been the principal fields of activity of IPPC since its organization in 1872 — had been matters of concern to the United Nations, in particular the Social Commission of ECOSOC, since 1946. Because of a desire to avoid duplication of effort, and because 18 of the 26 members of IPPC were also Members of the United Nations, representatives of IPPC and of the United Nations conducted negotiations in 1949 and 1950 for the integration of IPPC into the United Nations Secretariat