School was followed immediately by military training and service in the Navy, where he saw the last years of the war from the deck of a minesweeper in the Mediterranean (an experience that provided material for his novel, Smith, As Hero).

He and Eleanor were married in 1950 and, after a spell on a Houseboat on the Thames, they eventually set up home in a near-derelict and remote cottage in North Wales on the estate of Clough Williams Ellis (the architect and creator of the Portmeirion hotel), where his wife still lives today.

This led to opportunities for paid work and the family eventually moved to London, with the manuscript of his third novel (Henry’s War, 1962) lying on the back shelf of the car (where a bottle of his wife's ink slowly seeped into it for the duration of the journey, obliterating all but the edges of each page of tissue-thin typing paper – a disaster that Brooks later said had resulted in a better book).

Now settled in London, Brooks wrote his fourth novel (Smith, As Hero, 1964) and worked for New Statesman, The Sunday Times and the Royal Shakespeare Company at the Aldwych, becoming Literary Manager there in 1964.

This was a period of great upheaval in establishment theatre, with ground-breaking productions coming thick and fast (Peter Brook's Midsummer Night's Dream and Marat-Sade; works by Harold Pinter and Edward Bond; As You Like It with an all-male cast; Tom Stoppard's Rosencrantz and Guildenstern Are Dead) and the politics of the counter culture sometimes interfering with the smooth running of the RSC.

He wrote screenplays (Our Mother's House; Work is a Four Letter Word); television scripts for directors such as Karel Reisz and Ken Loach and a great number of important and memorable adaptations of classics for the stage (The Lower Depths, The Government Inspector (with Paul Scofield), Enemies (with a young Helen Mirren), The Forest, A Child's Christmas in Wales (co-written with Adrian Mitchell), The Cherry Orchard, Medea, The Wind in the Willows and many more).

The majority of these were for the RSC, where he worked closely with the director David Jones, but in later life he formed a fruitful relationship with Theatre Clwyd at Mold.

He had never been a good salesman of his most personal work (the novels and poems) and, in speaking of Smith, As Hero, he often lamented what he saw as a formal error in the book; this was a foray into metafiction with the introduction in a late chapter of a character called Jeremy Brooks (a device used two decades later by Martin Amis in Money).

There may have been another reason for his never having completed another novel: the period generally known as 'the sixties' had altered the world to such an extent that his voice, forged in wartime Britain, suddenly seemed outdated.

Writers like Ken Kesey, Robert Stone (a close friend of Brooks), Joseph Heller, Kurt Vonnegutt, spoke the language that people wanted to hear.