Lucy Brown, 30, actress, is engaged to Jeremy Wiseman, 31, who works in corporate finance

There is something cinematic about the love story of Lucy Brown and Jeremy Wiseman. Their eyes met across the pews of a school chapel, when they were both 13. Their first kiss was when they sneaked into the cricket pavilion. He was her first kiss, her first boyfriend. She was his first love.

No coincidence that she is a rising star of the British acting scene, best known for her role in the TV series Primeval. This story has the makings of an excellent British drama: Harry Potter meets Brief Encounter.

“I just think it’s great,” she says, “that it’s come full circle, I should have trusted my instincts when I was 13.”

Then, they had both nervously arrived as the new intake at Oundle, the mixed boarding school. On their first day, they were shepherded into the chapel. “As soon as I sat down, I remember seeing Jeremy, and immediately thinking, he’s rather delicious. It was a pivotal moment.”

Jeremy looked down the whole row of girls, “she just stood out to me, probably for the same reason that she still does. To me she looked quite similar then to how she does now.”

Within what would become a lifelong group of friends, Jeremy and Lucy were in an on-off relationship.

“We kept breaking up. It was for childish reasons, how you do, when you’re young. But we kept coming back to each other.”

Then, though, they parted finally aged 16. Lucy went to drama school, Jeremy to university. She was starting out in acting, and would go up and sit at the top of Primrose Hill, near where she lived, to look out at London and dream of love and success. Miles away, Jeremy was working in the City, thinking about her.It was only a year and a half ago that one of their old schoolmates put them back in touch.

“I remember so clearly walking through the doors, and seeing him standing at the bar, and feeling this rush of something. We talked and talked and talked until the bar closed. There was this wonderful ease. It just works. It fell into place without any effort. He is the most important person in my life, always will be.”

He knew she was the one “probably earlier than I would ever let anyone be aware of. I felt very certain very early on that this was something really amazing.” Both reflect that this certainty has something to do with the fact that they were influencing each other, back in those formative years.

“There is a picture of us all, aged 14, at a big party in the garden of Lucy’s house. I look at it and think, that girl is going to be my wife. I feel very lucky to have all that shared history.”

Just a few weeks ago, Jeremy lured her to Primrose Hill. He knew it was her favourite place in London, but they had never walked there together.

“I was going on about how I used to sit there, dreaming about being an actress, and he was saying, yes, yes, Lucy. And then he got down on one knee.”

Tourists gathered to watch. And then, in the best acting tradition, she demanded a retake of this crucial scene. “I knew in my head that he was someone I wanted to marry, but I was so blown away that it was actually happening, that I said, ‘can you do that again? I wasn’t even hearing it the first time’. He was like, ‘Oh God’, and back he went on one knee.”