He’s surely the most recognisable millennial in the world, with an eye-watering £150million fortune and legions of lovestruck fans.

So it’s no great shock that Harry Styles, the pop colossus and former One Direction heart-throb, is planning celebrations for his 30th birthday today on both sides of the Atlantic.

Yet despite his gargantuan fame and riches, Harry won’t be doing anything too flashy, say friends.

‘He likes to do the understated, classy thing, not gaudy and over-the-top,’ says one.

Best friend James Corden will be top of the guest list, as will the award-winning TV producer Ben Winston, who Harry sees as a big brother.

There will be a birthday surprise or two from Taylor Russell, the star’s actress girlfriend – while his beloved mum Anne, 56, will be there for her boy.

Down to earth star Harry Styles is spotted zipping around London on a rental Lime bike

Harry and his girlfriend Canadian model and actress Taylor Russell, 29,  in London

Harry shows off his toned physique at the Hampstead Ponds, just stone’s throw from Casa Styles

‘Harry is a perfectionist. He wants a great birthday that he will remember for ever,’ his friend tells me.

You can’t blame him for wanting the best.

Because for over 13 years – since he was a floppy-haired youth of just 16 – Harry has been a household name and the breakout star of Britain’s most successful all-male group since The Beatles.

Friends say that as he reaches this milestone birthday, Harry feels that his life is truly all coming together.

Those closest to him tell me they have never seen him as smitten with a girlfriend (and there have been many) than he is with Taylor, 29, a Canadian model and actress who made her name in Netflix sci-fi series Lost In Space and is a face of Spanish fashion house Loewe.

Like Harry, Taylor is said to be down to earth, with the pair shunning chauffeur-driven cars to zip around London on rental Lime bikes that cost just 27p per minute.

They have also been seen swimming together at the Hampstead Ponds, just stone’s throw from Casa Styles.

READ MORE: JENNI MURRAY: Now I know why Rebecca Ferguson’s career never took off…

Despite his wealth, sell-out tours and number-one solo albums, he remains grounded enough to travel around London with no security detail – including to visit celebrity-favourite gym Barry’s Bootcamp. He’s said never to refuse a selfie with his adoring fans.

One friend said: ‘Harry has had a lot of girlfriends over the years but with Taylor it all seems a little bit different.

‘There’s no starry behaviour, they just love living like a normal couple. She’s famous without the massive entourage or drama.’

The same can’t be said for some of Harry’s previous romances. Notoriously, he dated the late TV presenter Caroline Flack when he was just 17 and she was 34. Flack, who took her own life in February 2020, was trolled so viciously that the relationship came to an end.

Fellow megastar Taylor Swift soon caught his affections in 2012, and the pair were together for around a year. He is said to have inspired her songs I Knew You Were Trouble and – in a less subtle move – Style.

Next up came a trio of Victoria’s Secret models, among them Kendall Jenner, a scion of the Kardashian dynasty. They did not last long.

Yet another model, Camille Rowe, inspired his hit solo album Fine Line.

Harry’s most recent long-term relationship was with actress Olivia Wilde, nine years his senior, who he dated for almost two years until late 2022. Soon after, he was seen kissing sultry American sex symbol Emily Ratajkowski on the streets of Tokyo – not just a pretty face, with a successful podcasting career and a book to her name.

So if Harry really has finally settled down, perhaps it’s not before time.

Of his One Direction bandmates Louis Tomlinson, Niall Horan, Zayn Malik and Liam Payne, Harry has had by far the most successful career.

Since the band’s breakup in 2016, after selling 70million records and performing 531 concerts in 34 countries, his star has only continued to rise.

Three successful solo albums have been released, with the most recent, Harry’s House, shooting to Number 1 around the world. The single As It Was topped the charts in the UK and the US.

Forays into acting have been successful too, with starring roles in 2017 war epic Dunkirk and 2022 smash hit Don’t Worry Darling.

Harry rose to fame in pop group One Direction alongside bandmates Zayn Malik, Louis Tomlinson, Liam Payne and Niall Horan

Yet his old bandmates have enjoyed varying success.

I have been following One Direction since they first shot to fame in 2010. Shortly after they had been assembled as a band, I was summoned to interview them at their record label Syco’s London HQ.

I arrived to find them running around like puppies, each giving me a welcome hug. They couldn’t wait to tell me how much their lives had changed since they appeared on The X Factor.

My first meeting with the group was at the beginning of their rise to stardom, and I’m told that as the years went on and the band’s fame grew into a huge global juggernaut, cracks began to show.

Their bank balances bulged but the workload was gruelling.

With the band’s obsessive fans – known as ‘Directioners’ – trailing them everywhere, the boys were often unable to go out for days on end. Thousands would wait outside wherever they were staying just to glimpse their idols.

While Harry took to it with admirable self-possession – a tribute, perhaps, to his solid family upbringing in Holmes Chapel, Cheshire, under the watchful eye of mum Anne – for his former bandmates, that hasn’t been the case.

Just last October, fans were horrified by Liam Payne’s dishevelled appearance in a video to his 26million Instagram followers. Wolverhampton-born Liam announced ‘with a heavy heart’ that he was cancelling a series of concerts in South America due to a ‘bad’ kidney infection.

Friends told the Mail they feared for his wellbeing – and his future.

I was reminded of my first meeting with Liam, when he appeared more excited than the rest of the band about his unexpected success. Dressed in a navy hoodie and jeans, he insisted with a wide smile that he was ‘lovin’ it’ – although he added poignantly that his mum Karen missed him and cried a lot when he was away.

Infamously, Liam went on to date ex-Girls Aloud singer Cheryl Tweedy, ten years his senior, who was a judge on The X Factor when he auditioned in 2010. Shortly after she gave birth to their son, Bear, now six. The pregnancy, say friends of Liam, came as a ‘big surprise’ to him – and eventually he and Cheryl split up.

Bradford boy Zayn Malik was first to leave the band in March 2015 after rumours that he was habitually taking illegal drugs.

He sensationally quit the mega-group after arriving late to a promotional tour in America, only to be sulky and monosyllabic in interviews. His relationship with Little Mix singer Perrie Edwards had ended and he was, friends now tell me, ‘struggling with life back then’.

Moving to Los Angeles to attempt a solo career, he began dating supermodel Gigi Hadid and they went on to have a baby girl named Khai. In 2021 he was dropped by his US record label, RCA, after claims that he was smoking cannabis and behaving erratically.

Harry grew up in Holmes Chapel, Cheshire, with his mother Anne Twist, late step-father Des and his sister Gemma

Taylor made her name in Netflix sci-fi series Lost In Space and is a face of Spanish fashion house Loewe

Soon after he was charged with harassing Gigi and her mother Yolanda after an alleged altercation at the Pennsylvania home where he had moved for a quieter life.

Last week, Zayn made a return to the limelight, attending multiple shows at Paris Fashion Week.

Like Liam, Zayn wasn’t always so affected by fame.

Four months after our first meeting, he approached me at the Brit Awards to say he remembered the red blouse I was wearing and how much he enjoyed our interview. Trust me, few pop stars are so courteous.

As for pint-sized, Beatle-haired Louis Tomlinson, he too was hit by the One Direction curse. After launching a solo career, Louis went back to his roots in 2017 when he joined The X Factor as a judge alongside Simon Cowell, Robbie Williams and Robbie’s wife Ayda Field.

In December 2016, Louis’s mother, Johannah Deakin, died of leukaemia at the age of just 43. Louis said at the time: ‘Every song I wrote felt, not pathetic, but that it lacked true meaning to me.’

More tragically still, in March 2019 his younger sister Félicité died from an accidental overdose.

In 2023, Louis began his own ‘world tour’ – playing venues noticeably smaller than Harry’s.

Happily, Irish heart-throb Niall Horan, always deemed the quiet one, seems to live a more normal life. Some years ago, he founded his own management company for golfers, keen to get women into the sport.

These days he commands few headlines despite his wealth – estimated at around £40million – and splits his time between London and Los Angeles.

As Harry celebrates his big day, one wonders what is next for the man who has everything.

‘We just want him to settle down, get married and have babies,’ says a close associate of the star.

‘Wouldn’t that be the icing on the cake?’