From the website Lost Hospitals of London:
“The financier and philanthropist Sir Ernest Cassel (1852-1921) had been greatly affected by the consequences of WW1, especially by those who had been shot for cowardice…In 1919, with the help of Sir Maurice Craig (1866-1935), he purchased Swaylands, a large country house in Penshurst, Kent, in which to establish a hospital for civilian psychological casualties affected by the war. Following the house purchase and equipping of the hospital, some £173,000 of his £225,000 endowment remained, and this money was set aside to be used to help less well-off patients.
The Cassel Hospital for Functional Nervous Disorders opened in May 1921 to provide systemic treatment for the psychoneuroses. Dr Thomas Arthur Ross (1875-1941) was appointed its first Medical Director.
The Hospital could accommodate 60 patients, primarily members of the educated classes (sic) who were unable to afford the expense of care and treatment in a nursing home. Although the upkeep of the building and cost of treatment were borne by the institution, patients stayed between two and six months and were charged a contribution towards their own maintenance.
During WW2 the Hospital was evacuated to Stoke-on-Trent.
In 1947 the Cassel Foundation purchased the Lawrence Hall Hotel, a late 18th century building originally known as Morgan House, at Ham Common in Richmond.
The Hospital reopened there in 1948, becoming part of the NHS under the control of the South West Metropolitan Regional Health Authority. Dr Tom Main (1911-1990), who had been appointed Medical Director in 1946, was determined to develop it as a therapeutic community to treat personality disorders, following experiments at the Northfield Military Hospital, a large military psychiatric hospital just outside Birmingham.
(From Wikipedia: Thomas Main was born on 25 February 1911 in Johannesburg, where his father was a mine manager who had emigrated there from England. At the start of World War I his mother returned to English with Main and his two sisters, while his father joined the South African Army. Main was educated at the Royal Grammar School, Newcastle-upon-Tyne before studying medicine at Durham University, graduating in 1933 and becoming a doctor in 1938. Specializing in psychiatry, he gained a Diploma in Psychological Medicine from Dublin in 1936. In 1937 he married Agnes Mary (Molly) McHaffie.
Main worked as superintendent at Gateshead Mental Hospital. During the Second World War he joined the Royal Army Medical Corps as an adviser in psychiatry, attaining the rank of lieutenant colonel and working at the Northfield Army Hospital for the treatment of war neuroses. After the war he went to Cassel Hospital, becoming Medical Director there in 1946 and working there for the next thirty years.
Training as a psychoanalyst under Michael Balint, he was supervised by Anna Freud, Melanie Klein and Paula Heimann. He helped found the Institute of Psychosexual Medicine, and served as its Life President. He also served as vice-president of the Royal College of Psychiatrists, and was a co-editor of the British Journal of Medical Psychology. He died in Barnes, London on 29 May 1990, aged 79.)
In 2008 the Henderson Hospital closed, and its remaining patients were transferred to the Cassel Hospital.”
From its website: “The Cassel Hospital is an NHS Tier 4 specialist personality disorder service and is part of West London Mental Health Trust.
We deliver combined psychosocial and psychoanalytic treatment through Inpatient and Outreach treatment programs.”