Cooper Hewitt says...
Group X was formed in 1920 by a group of ten British artists, many of whom had been members of the Vorticists and the London Group prior to World War I. The ten Group X artists were Jessica Dismorr, Frank Dobson, Frederick Etchells, Charles Ginner, Cuthbert Hamilton, Wyndham Lewis, E. McKnight Kauffer (the group’s Secretary), William Roberts, John Turnbull, and Edward Wadsworth. Group X was dissatisfied with the perceived stagnancy of other avant-garde groups in the post-war period. Group X aimed to revitalize a progressive British art scene and revive the intentions set out by Lewis’ Vorticist group prior to the war. [1] Ginner, Kauffer, and Lewis organized the group’s first (and only) public exhibition in 1920. The exhibition took place at the Mansard Gallery, located on the fourth floor of Sir Ambrose Heal’s London furniture store, Heal & Son. [2]
[1] http://www.oxfordartonline.com.libproxy.newschool.edu/groveart/view/10.1093/gao/9781884446054.001.0001/oao-9781884446054-e-7000035139?rskey=tEsPZD&result=1
[2] Interesting chapter by Arlene Leis about Group X Catalogue: http://www.wyndhamlewis.org/images/JWLS-essays/2012/jwls-2012-leis.pdf
