The International Peace Bureau (IPB) was officialy founded in 1891 at the International Peace Congress in Rome as a result of the report of the Commission appointed the previous year by the London Congress. Its Statutes were approved and its first Council elected in August 1892. Frederik Bajer of Denmark became its first President. The seat of the Bureau was initially located in Bern ; as a consequence of the foundation of the League of Nations it was moved to Geneva in 1924. After World War II the IPB split and was eventually disbanded in 1959. Meanwhile, a group of reformers founded the International Liaison Committee of Organizations for Peace (ILCOP) in 1949, which later took up again the name of the IPB. The Office was reopened in 1964.
The IPB served as the Permanent Secretariat to the Universal Congresses. Besides acting as liaison between various peace organizations, the Bureau assembled a valuable specialized library and published a considerable number of pamphlets, periodicals and books.