The dashing younger brother of the Princess of Wales celebrates his 37th birthday today. 

As Kate undergoes preventative chemotherapy, James Middleton has vowed to join the rest of the family in standing by her side.

James is the youngest child of Carole and Michael, aged 69 and 74. His sisters are  Pippa, 40, and Kate, 42.

Not to be overlooked is James' wife and 'soulmate', French financier Alizée Thevenet, with whom he shares a son named Inigo. 

James Middleton is married to French financier Alizée Thevenet. They are pictured  here together with their dogs

The couple met in 2014 at Chelsea's South Kensington Club.

Writing in The Telegraph in 2021, James explained that his dog, Ella, 'made a beeline for Alizée'. 

Feeling rather embarrassed, James approached the financier to apologise and bring Ella back.

However, Alizée mistook him for a waiter and 'ordered her drink while continuing to stroke Ella, who at this point was on her back lapping up the attention.' 

The lovebirds became engaged in September 2019, but were forced to delay their wedding twice due to the Covid pandemic.

They finally tied the knot in Bormes-les-Mimosas, Provence, in 2021.

Alizée, who has lived and worked in London for several years, is currently a director at Treasury Spring, a fin tech firm that uses digital pipelines to connect cash rich firms to institutional borrowers.

She is the daughter of retired diplomat Jean-Gabriel Thevenet, who is very fond of James and has described Alizée as 'deliriously happy' with her husband.

The couple live in a  £1.45million home  in Bucklebury, west Berkshire, the village that Kate, Pippa and James grew up in.

James is an ambassador for the Pets As Therapy charity and shares a love of dogs with his partner. They currently own six canines - in addition to a precious rescue lamb.

James and Alizée are pictured at the switching on of the Bulgari  Serpenti Christmas lights in 2021

Alizée feeds the couple's adorable rescue lamb as two of their dogs watch on

James Middleton laps up the sunshine with his wife Alizee Thevenet, then pregnant with their son Inigo 

James shares a photograph of his newborn son's hand alongside a portrait of his beloved dog Ella 

But their idyllic countryside life has not been without its challenges. 

The entrepreneur, who is a mental health advocate, has voiced his experiences with major depressive disorder on numerous occasions.

In 2019, James wrote an essay for the Daily Mail, which read: 'Each night sleep eluded me. A cacophony of imaginary noises rang in my head. It felt as if ten different radio stations were competing for airtime and the din was ceaseless and wearying.

'During the day I'd drag myself up and go to work, then just stare with glazed eyes at my computer screen, willing the hours to tick by so I could drive home again.'

He also emphasised the pivotal role of his pets, especially black spaniel Ella, in aiding his recovery.

'I recognise, too, the role my dogs - Ella, Inca, Luna, Zulu and Mabel - have played in my recovery. 

'Ella, particularly, has been my constant companion for ten years and she’s been with me to all my therapy sessions. In her own particular way, she has kept me going.'

James holds his family dear, acknowledging their crucial role in his life, especially during his battle with clinical depression. 

'My sisters came to some of my therapy sessions,' he said. 'They've always been there during difficult times and they were at my side during the hardest of times as well. For that, I am forever grateful.'

James posted a childhood photograph of him and sister Kate following her cancer diagnosis

James and Kate arrive at The Concert For Diana at Wembley Stadium in 2007

At 37 years old, James Middleton has taken on the role of a protective brother, offering unwavering support to Kate as she undergoes chemotherapy treatment. 

Shortly after the Princess publicised her cancer diagnosis, he shared a previously unseen photograph of the pair as children.

He wrote: 'Over the years, we have climbed many mountains together. As a family, we will climb this one with you too.'

James also demonstrated his loyalty to Kate at her wedding to Prince William, reciting a Bible passage to a global audience of two billion, despite suffering from dyslexia.

He had to re-type the passage phonetically in order to learn it off by heart.

'At the end of the day, whether it was a little church or Westminster Abbey didn't matter. It was me, as a brother, doing a reading for my sister and her husband at their wedding and I wanted to do it right,' he said.

Living in close proximity, the Middleton family enjoys a close and interconnected relationship. 

Similar to James and Alizée, Carole and Michael are based in Bucklebury, a 40-minute drive from Windsor, while Pippa resides in Berkshire.

'We spend a lot of time together. We still do a lot together as a family. And I think that's really the heart for all of us is having a really close family that we can sort of be normal with each other, treat each other normally,' Pippa previously said.

'And that's sort of kept us all, you know, affixed to the ground.'

Carole and Michael were able to provide a privileged upbringing for their children, sending all three to the prestigious Marlborough College in Wiltshire.

Speaking to Tatler, insiders who knew the Middleton children at school said the family was notorious for 'doing everything to the very highest of standards'.

'There were huge picnics on sports days, the smartest tennis rackets - that kind of thing. It made the rest of us all feel rather hopeless,' a fellow parent told the publication.

The institution is said to have transformed the future Queen from a 'shy bullied girl' to a 'hockey captain that snagged a Prince'.

In 2023, James didn't shy away from expressing his love for his mother, Carole, in a touching Mother's Day tribute, complete with a heartfelt post and candid snapshot of the duo. 

The caption read: 'You make my world go around. Happy Mother’s Day to all the mothers out there and especially to this one.'

On International Women's Day, he shared a picture showing Alizée tenderly feeding a newborn lamb as he praised his wife and the other women in his life.

'Celebrating International Women's Day through our love of dogs, because they are Woman's best friend too,' he wrote.

'I am fortunate to be surrounded by incredible women, my wife, my mother, my sisters, my friends, my colleagues and many more who inspire me every day.'

James photographed with his mother Carole on his wedding day

Alizée looks lovingly at her husband in a recent Instagram snap

James' current venture, James & Ella, is a mail order dog food company that offers freeze-dried, raw, organic dog food

An experienced entrepreneur, James has founded multiple companies, including boomf, specialising in personalised marshmallows.

His current venture, James & Ella, is a mail order dog food company that offers freeze-dried, raw, organic dog food. 

The brand was inspired by his beloved spaniel, who passed away last year.

James has since written a book dedicated to his canine, Meet Ella: The Dog Who Saved My Life, which will be released in September.