The origin of the Tournament dates back to the late 1970s in the USSR. The National (All Union) Olympiad of the USSR previously was based on a system that gave relatively little opportunity to students in the larger republics such as Russia and Ukraina. The first Tournament was known as the Olympiad of Three Towns (Moscow, Leningrad and Riga) and was held in the 1979-1980 academic year. Participation quickly grew and the Tournament changed to its current name in the following year. The Tournament had difficulty in obtaining political recognition in its early years, but its popularity grew and it finally won recognition in 1984 when it became a subcommittee of the USSR Academy of Sciences. The support of the USSR Academy of Sciences allowed the Tournament to become international. This attracted entries initially from Eastern Europe, particularly Bulgaria, where a national committee was formed. In 1988 the city of Canberra entered the 10th Tournament, becoming the first Western and English-speaking city to participate. Sweden first participated in the 18th Tournament, 1996.