Greek civilisation : healing temples, dialogue groups (Plato)
18th century : Anton Mesmer 'Animal Magnetism'
1907 : JH Pratt, physician dealing with tuberculosis patients in USA
1913 : Freud, 'Totem and Taboo', psychoanalytic processes in anthropology and social groups
1920 : JL Moreno, USA, first use of the term 'group therapy'
1921 : Freud, 'Group psychology and the analysis of the ego', the relationship of groups to their leaders (church and army)
Post 1920s : A Adler, psychiatric day hospitals and therapeutic clubs
1939 : P Schilder, "Some of the patients could not have been treated individually with classical analysis. They reacted only in the group
Post WW2 in the USA
1943 : SR Slavson, educationalist and self-taught psychoanalyst, founder of the American Group Psychotherapy Association
1946 : work of Carl Menninger, Chief of Army Psychiatry
1946 : JL Moreno, 'Psychodrama'
Post WW2 in the UK
1945: Bion, Rickman, Foulkes and Main, the Northfield Experiment in Northfield Military Hospital
1946: W Bion and H Ezriel, Tavistock Institute, applied psychoanalysis in groups
1946: T Main, Medical Director, Cassel Hospital, psychosocial nursing
1949: M Jones, the Henderson Hospital, 'the therapeutic community'
1952: SH Foulkes and ET Anthony, Group Analytic Society
1961: M Balint 'balint groups' (GPs/patients)
1971: Institute of Group Analysis
1990s: P de Mare, Median Group Section, Group Analytic Society