Adopted on 14 April 1961 by the United Nations Conference on Diplomatic Intercourse and Immunities held in Vienna, Austria, from 2 March to 14 April. The Conference also adopted the Optional Protocol concerning the Acquisition of Nationality, the Optional Protocol concerning the Compulsory Settlement of Disputes, the Final Act and four resolutions annexed to that Act. Done at Vienna, on 18 April 1961. Entered into force on 24 April 1964.