I was, in Michael Coveney’s parlance, one of Peter Gill’s acolytes. I knew him in his autumn; after he’d directed his last play for the National, after he’d moved from Harriet Devine’s house in Hammersmith, where he lived for most of his adult life, into his flat a little further down the river. For 20 years we met there, or in the community centre when we held workshops with actors to help him develop material. One day he told me I should write a book about him: “I introduced postmodernism to the theatre, darling.” I was proud he’d asked me, a feeling that only slightly receded when I read an article by Nina Raine a few years later, in which she revealed he’d suggested the same thing to her. Now Peter has died, I have a strong feeling I should be writing about him again.

I think the framework hasn’t yet been created to talk about Peter’s significance. When I was researching my book about him, I went to interview his friend Bill Gaskill. What we talked about most that day was Wordsworth, and over the years I’ve come to see that as significant. It was Wordsworth who proposed that literature should speak in “the real language of men”. That project flowered a century later in the work of DH Lawrence, who broke free of the conditions of his birth to revolutionise English literature. Lawrence tore through almost every barrier he encountered, for better or worse, in every aspect of his life – but he couldn’t break into the theatre. A “vertical invader” from a peasant class, to borrow John Berger’s description of Picasso, Lawrence reshaped the artistic landscape, but the English theatre made no room in his lifetime for the stories of working people. It took another vertical invader to complete that revolution: a docker’s son from Cardiff who took Lawrence’s plays, placed them at the centre of the world and said, once and for all, “as much happens for you as for other people”. That was Peter’s achievement. He showed us anywhere could be the centre of the world.

And did so beautifully, in a Keatsian sense. When a stage direction required the baking of bread, Peter had his company bake bread, however long it took. When he ended up in hospital during tech for the Lawrence trilogy, and his assistant came to his bedside to say they were planning to use dry ice to show the bread burning, Peter asked him: “Who do you think I am, Franco Zeffirelli?” He used theatre to tell the truth.

Susan Sontag wrote of Thomas Hardy that he was the only great novelist who was also a great poet. I would gently make the claim that Peter Gill achieved a place of similar distinction: the only great playwright who was also a great director. It was his time around the Court that forged him. Allow me to get into the record what he said about the white heat of that period. He began by paraphrasing Adorno, then added something revolutionary of his own: “Once we knew about Auschwitz we didn’t know how to say anything that meant anything. The bind was that the only moral act in the light of that was to try to say something, you see?” That Beckettian second sentence – the determination to go on, not to accept humanity in ruins but to recognise it and then to seek to speak and live again – is the foundation of every good play anyone’s written since. Peter was in the room when that thought formed. Its radical compassion mustn’t leave the world with him.