Founded in 1851 as the then Third Lancashire County Lunatic Asylum, the hospital was repeatedly expanded until the 1980's when a mixture of administrative changes and changes in policy saw patient services transfer to newer facilities and care in the community.

The facility was designed by Harvey Lonsdale Elmes and opened as the Third Lancashire County Lunatic Asylum on 1 January 1851.

[2] In 1877 a new annexe was designed by George Enoch Grayson and Edward Ould and constructed to the north-west of Rainhill Road.

[1] The Avon Division was noted for its distinctive water towers and linear design.

[4] From 1943 to 1944 the Medical Officer in Charge was Surgeon Captain Joseph Roland Brennan RN.