Entering Graylingwell Hospital near Chichester in the 1960s was like being transported into another world.

Barone Hopper vividly recalls his first visit there on a wet, dark day back in 1967, coming across the gaunt main building, erected as a lunatic asylum 70 years earlier.

Hopper, who was training as a mental nurse, was given friendly but limited assistance as he tried to find his way round the endless rooms and corridors.

But he stayed for more than 30 years and retired in 2000 with an unmatched knowledge of the institution.

Now he has written an enormous 700-page book, mingling his own experiences with episodes of earlier history at a hospital which dealt with patients from most of West Sussex.

He says: “It would be lovely to recall only tales of a happy, often humorous place and to depict numerous scenes wholly without dour sickness, death or unhappy disorder – even of occasional chaos.”

But he discounts prevailing myths which abounded among those who had never been there that Graylingwell was a place of Gothic horror.

It was a huge institution in substantial grounds that became home not only for the hundreds of inmates but also for the staff chosen to look after them.

The hospital was big enough to have its own farm, while a tower which served as a local landmark helped produce Graylingwell’s own water supply.

Graylingwell was opened in 1897 after completion was delayed by a building strike. The first superintendent was Dr Harold Kidd, whose humanity helped make it a less fearsome place than many others.

Kidd stayed there for 30 years and Hopper says he was far ahead of his time. Early on he changed its name from the West Sussex Asylum to Graylingwell Hospital.

Hopper was able to cover the whole history of Graylingwell by interviewing people whose parents had worked there, and they included a son of Dr Kidd.

It was used as a hospital during the First World War when there was a desperate need in the South for more beds, and the military did not leave until 1920.

Even in the 1960s, Graylingwell was changing from the early days. Hopper recalls an experimental day hospital which provided a community health service.

Patients were able to return home at evenings and weekends.

He also remembers taking some patients out with other members of staff for pleasant walks around country lanes.

But there were other patients who would never leave their wards for a moment unless made to do so.

He says the dedicated and unremitting quality of care by most of his colleagues to patients, even the really difficult and disturbed ones, had to be seen to be believed.

Over the years, huge advances in the care of patients with mental problems led to the closure of the old asylums and the widespread use of care in the community.

Graylingwell, like the other two large Sussex mental hospitals, St Francis at Haywards Heath and Hellingly near Hailsham, has been earmarked for housing, although traces of the old buildings remain.

Hopper has performed a public service with his book and there is a second volume to come. He helped make the history he has written about.

* Better Court Than Coroners: Memoirs Of A Duty Of Care by Barone Hopper (PV Publications, £24.99) is available from the author at 26 Sandfield Avenue, Littlehampton BN17 7LL.