International Congress of Mathematicians

The organizing committees of the early ICMs were formed in large part on an ad hoc basis and there was no single body continuously overseeing the ICMs. Following the end of World War I, the Allied Powers established in 1919 in Brussels the International Research Council (IRC). At the IRC's instructions, in 1920 the Union Mathematique Internationale (UMI) was created.[10] This was the immediate predecessor of the current International Mathematical Union. Under the IRC's pressure, UMI reassigned the 1920 congress from Stockholm to Strasbourg and insisted on the rule which excluded from the congress mathematicians representing the former Central Powers. The exclusion rule, which also applied to the 1924 ICM, turned out to be quite unpopular among mathematicians from the U.S. and Great Britain. The 1924 ICM was originally scheduled to be held in New York, but had to be moved to Toronto after the American Mathematical Society withdrew its invitation to host the congress, in protest against the exclusion rule.[4] As a result of the exclusion rule and the protests it generated, the 1920 and the 1924 ICMs were considerably smaller than the previous ones. In the run-up to the 1928 ICM in Bologna, IRC and UMI still insisted on applying the exclusion rule. In the face of the protests against the exclusion rule and the possibility of a boycott of the congress by the American Mathematical Society and the London Mathematical Society, the congress's organizers decided to hold the 1928 ICM under the auspices of the University of Bologna rather than of the UMI.[10] The 1928 congress and all the subsequent congresses have been open for participation by mathematicians of all countries. The statutes of the UMI expired in 1931 and at the 1932 ICM in Zurich a decision to dissolve the UMI was made, largely in opposition to IRC's pressure on the UMI.[10]

At the 1950 ICM the participants voted to reconstitute the International Mathematical Union (IMU), which was formally established in 1951. Starting with the 1954 congress in Amsterdam, the ICMs are held under the auspices of the IMU.

The Soviet commemorative stamp for the 1966 Congress in Moscow

The Soviet Union sent 27 participants to the 1928 ICM in Bologna and 10 participants to the 1932 ICM in Zurich.[13] No Soviet mathematicians participated in the 1936 ICM, although a number of invitations were extended to them. At the 1950 ICM there were again no participants from the Soviet Union, although quite a few were invited. Similarly, no representatives of other Eastern Bloc countries, except for Yugoslavia, participated in the 1950 congress. Andrey Kolmogorov had been appointed to the Fields Medal selection committee for the 1950 congress, but did not participate in the committee's work. However, in a famous episode, a few days before the end of the 1950 ICM, the congress' organizers received a telegram from Sergei Vavilov, President of the USSR Academy of Sciences. The telegram thanked the organizers for inviting Soviet mathematicians but said that they are unable to attend "being very much occupied with their regular work", and wished success to the congress's participants.[15] Vavilov's message was seen as a hopeful sign for the future ICMs and the situation improved further after Joseph Stalin's death in 1953. The Soviet Union was represented by five mathematicians at the 1954 ICM in Amsterdam, and several other Eastern Bloc countries sent their representatives as well. In 1957 the USSR joined the International Mathematical Union and the participation in subsequent ICMs by the Soviet and other Eastern Bloc scientists has been mostly at normal levels.[15] However, even after 1957, tensions between ICM organizers and the Soviet side persisted. Soviet mathematicians invited to attend the ICMs routinely experienced difficulties with obtaining exit visas from the Soviet Union and were often unable to come. Thus of the 41 invited speakers from the USSR for the 1974 ICM in Vancouver, only 20 actually arrived.[4] Grigory Margulis, who was awarded the Fields Medal at 1978 ICM in Helsinki, was not granted an exit visa and was unable to attend the 1978 congress.[4][16] Another, related, point of contention was the jurisdiction over Fields Medals for Soviet mathematicians. After 1978 the Soviet Union put forward a demand that the USSR Academy of Sciences approve all Soviet candidates for the Fields Medal, before it was awarded to them.[4][16] However, the IMU insisted that the decisions regarding invited speakers and Fields medalists be kept under exclusive jurisdiction of the ICM committees appointed for that purpose by the IMU.[4][16]