Bridget Galton ventures down to the disused Aldwych tube station to catch up with the founders of the scheme, who met at a Hampstead reading group.

It was reading a scene from As You Like It – where lovesick Orlando pins his terrible sonnets to trees - that sowed the seed for Poems on the Underground.

The play reading group who met regularly in South Hill Park, Hampstead discussed putting up good poetry in public places – if not on trees then say the ad hoardings on tube trains.

Backed by poets Cicely Herbert and Gerard Benson, writer Judith Chernaik sent a letter to tube bosses which yielded a match funding deal if they could raise £1,000.

More than 500 poems later, the project, which has spawned copycat schemes in Dublin, New York, Paris, St Petersburg and Shanghai, celebrates its 30th birthday.

Chernaik and Herbert were joined by poets Fleur Adcock, John Hegley, Grace Nichols and David Constantine to mark the occasion at disused Aldwych tube station. It was a working station three decades ago when the founders launched the initiative, but since 1993 the Grade II listed station has been used by film crews from Sherlock to Atonement.

London Underground MD Nick Brown said: “It was on a wet January morning that Poems on the Underground was launched; the brainchild of Judith Chernaik who wanted to bring poetry to a wider audience. What a vision and inspiration! The founders climbed aboard a tube train and brought poetry alive with their readings. It has inspired other cities to follow and proved a great way of introducing the public to a diverse range of poets both classic and contemporary, national and international.”

Chernaik, who lives in Gospel Oak and has published several novels, says: “It didn’t take any persuasion. The Underground liked the idea and everyone from publishers, the Arts Council, and the British Council wanted to help.

“I have always loved poetry. I have never thought of it as elitist. As soon as the poems went up in those advertising spaces they seemed to belong there. Somehow it felt natural. After all, children start language with nursery rhymes and folk songs then go onto verse.”

The first selections were “very informal”

“It was three friends sharing their pleasure in poetry. What made the programme work was something we came up with by accident, that we should have at least two living poets. We did a lot of reading of books and newly published poems and put that with our own knowledge and love for the poetry of the past – that balance of old and new is what people like. Seeing something they recognise from school but in a different context, or something from contemporary life. It’s not intrusive, people can read it or not, it is the individual voice reaching the individual reader.”

Hampstead and Highgate poets featured on the hoardings have included Keats, Betjeman, Herbert and Adrian Mitchell whose widow Celia read a poem about her commenting that “When Judith started this she and her family were living in my house in South Hill Park that’s how she got to know (neighbour) Cicely and how it all got off the ground so I claim some responsibility!”

Celia, Celia:

When I am sad and weary

When I think all hope has gone

When I walk along High Holborn

I think of you with nothing on

She added: “It was written when I was a bit younger! It used to make him very happy to see people smiling on the tube when they read that.”

Raised in Golders Green, Benson died in 2014, but his widow Catherine read his poem Riddle which inspired many readers to try to work out the solution.

And reading one of her father’s poems, among the first selected, Seamus Heaney’s daughter Catherine commented that despite being known as a rural writer “he must be one of the only poets who named a volume after a tube line” (District and Circle)

Herbert, who lives in Hampstead, said: “We would have discussions but when we selected poems they had to be short, 14 lines or less to fit the space. It’s made a big difference to what people feel about poetry. Children have always loved reading poems but in the past it’s been badly taught in schools and people became frightened of it. Projects like this and poets going into schools has brought poetry to the people.”

Chernaik added: “We are very pleased to have given pleasure to so many people over the years.”