Priory was acquired by Doughty Hanson in June 2002. At the time of the acquisition it was the largest independent provider of mental health and rehabilitation services in the UK.
Under Doughty Hanson's ownership it had a national presence with over 42 locations, over 2,000 beds and a staff complement approaching 4,500.
The company had hospitals providing acute psychiatric services covering conditions such as addictions, eating disorders and depressive illness.
It also ran specialist schools and adolescent psychiatry units as well as centres treating patients with acquired brain injuries. The group operated a number of low and medium secure units for people with enduring mental illness.
Priory was sold in July 2005 in a transaction valued at £875m.