Team 10 — just as often referred to as Team X or Team Ten — was a group of architects and other invited participants who assembled starting in July 1953 at the 9th Congress of Congrès Internationaux d'Architecture Moderne−C.I.A.M. and created a schism within C.I.A.M. by challenging its doctrinaire approach to urbanism.
The group's first formal meeting under the name of Team 10 took place in Bagnols-sur-Cèze in 1960. The last, with only four members present, was in Lisbon in 1981.
Team 10's core group consists of the seven most active and longest-involved participants in the Team 10 discourse, namely Jaap Bakema, Georges Candilis, Giancarlo De Carlo, Aldo van Eyck, Alison and Peter Smithson and Shadrach Woods. Other participants and their contributions are of course important, particularly those of José Coderch, Ralph Erskine, Pancho Guedes, Rolf Gutmann, Geir Grung, Oskar Hansen,Reima Pietilä, Charles Polonyi, Brian Richards, Jerzy Soltan, Oswald Mathias Ungers, John Voelcker, and Stefan Wewerka.
They referred to themselves as "a small family group of architects who have sought each other out because each has found the help of the others necessary to the development and understanding of their own individual work." Team 10's theoretical framework, disseminated primarily through teaching and publications, had a profound influence on the development of architectural thought in the second half of the 20th century, primarily in Europe.