In December 1946 the General Assembly requested that the Economic and Social Council prepare a draft genocide convention with a view to its adoption at the 1947 session of the Assembly. The Secretariat prepared a draft convention with the assistance of three experts in international criminal law, Raphael Lemkin, Henri Donnedieu de Vabres and Vespasian Pella. However, the Economic and Social Council did not complete consultations with Member States in 1947. In early 1948, the Council established an Ad Hoc Committee composed of representatives of several Member States which prepared a revised draft. This draft was then revised and adopted by the Sixth Committee of the General Assembly in December 1948. The Assembly also adopted resolutions calling for consideration of the establishment of an international criminal court and for the extension of the Convention to colonies. The Convention entered into force in January 1951 after the threshold of twenty ratifications or accessions had been achieved.