The Kilburn Festival returns on Sunday and this year, there’s an extra special reason to celebrate in Kilburn Grange Park, because the much-loved green space is in its centenary year.

It’s the green lung that’s given Kilburn space to breathe for 100 years.

But it bears remembering that the vital pocket of urban greenery nearly never was.

For had its early 20th century owners had their way, the 7.9 acres of parkland we enjoy today might have been a skating rink, or even an aeroplane factory.

And it’s a story straight from a BBC period drama.

It involved a landed widow with her flamboyant Marquis lover – and dreams of giving the grounds of Kilburn’s last great mansion to the community.

Blocking the way were her late husband’s family who planned to sell the land commercially.

Dick Weindling and Marianne Colloms, who have written a number of books about Kilburn’s history, charted the drama through public archives.

Marianne said: “The Grange was in the poorest and most crowded part of Kilburn. Row upon row of homes, each built for one family but occupied by three, surrounded it.

“At that time there were almost 4,000 children under the age of 15 in the Kilburn ward of Hampstead.

“Yet the streets were the only open space outside the playgrounds of the council schools.”

The Grange’s last occupier was the park’s first great hope.

Widow Ada Peters lived there since the death of her wealthy coach-maker husband.

She took a lover, the colourful Marquis de Leuville; a Victorian poet.

Besotted with the Marquis – and against the wishes of her husband’s family – she offered in 1901 to sell its lands to create a park for the people.

A committee was set up to drive it forward and fundraising got under way, but then came a bombshell.

Under the terms of her husband’s will, Mrs Peters had no claim to the Grange beyond being its ‘tenant for life’ and the plans were blocked.

When she died soon after, the Grange estate was quickly prepared for auction.

And it was advertised as ideal for a “skating rink, theatre, cinema, music hall, aeroplane factory, exhibition ground or residential flats, bringing untold wealth for the lucky purchaser.”

The plans for a park seemed doomed.

Eventually entertainment magnate Oswald Stoll took the plunge – building the Grange Cinema (now the Universal Church).

But Stoll never developed the land entirely, allowing the London County Council to buy nearly eight acres for £19,500 – or about £1.6m in today’s money - for Kilburn Grange Park, which opened its gates on May 1, 1913.

Today the park is filled with oak, yew, ash, silver birch and hornbeam trees and residents enjoy the fitness facilities, football and basketball courts, and children explore the award-winning adventure playground.

Dick added: “It’s hard to imagine Kilburn without the green lung of Grange Park today.”