At just 14 years old, he is the Queen's youngest grandchild and has largely grown up away from the public spotlight.
But tonight James, Viscount Severn, the younger son of Prince Edward and Sophie Wessex, bravely joined his older sister Lady Louise Windsor and his cousins Prince William and Prince Harry for a poignant and moving vigil around the late monarch's coffin. Along with Peter Phillips, Zara Tindall, Princess Beatrice and Princess Eugenie, James walked in formation into Westminster Hall and stood at the side of his grandmother's coffin. He bowed his head as he positioned himself in between Peter and Eugenie while tearful mourners, who had waited in a long queue, came to pay their respects.
His parents watched on during the vigil with mum Sophie becoming tearful as she proudly watched both of her children carry out the emotional vigil.
Over the last few months, James has made several high-profile appearances such as at the Commonwealth Games and the Queen's Platinum Jubilee celebrations.
He was born in December 2007 at Frimley Park Hospital in Surrey - close to his parents' home of Bagshot Park.
His full name is James Alexander Philip Theo - with the middle name Philip clearly a nod to his late grandfather Prince Philip.
Proud dad Edward described his newborn son as "very cute and very cuddly" and at the time of his birth, he was eighth in line to the throne - although he has now slipped to 14th.
When his parents Edward and Sophie married at St George's Chapel in Windsor in 1999, they were granted the titles Earl and Countess of Wessex.
And at the time, Buckingham Palace also announced that any of their future children would not be styled as prince or princess.
This means that James and his older sister Louise, are titled as children of an Earl - and don't use the HRH style.
James' title is Viscount Severn - one of his dad Edward's subsidiary titles - and the decision was said to be part of his parent's hopes for their children to have as normal a childhood as possible.
At 14 years old, James is firmly still in school - with him believed to be educated close to the family home.
Both James and sister Louise have often been described as among the Queen's favourite grandchildren - and shared a close relationship with her.
Each summer, they would spend quality time with their grandmother on her Balmoral estate, where James is said to be "rather good at flipping burgers" during family barbecues.
And during his moving tribute to his mother, James' dad Edward touched on the teenager's shared loves and passions with the Queen - and the late Philip.
He said: "The Queen's passing has left an unimaginable void in all our lives. Sophie and I have taken huge pleasure in seeing our James and Louise enjoying the places and activities that their grandparents loved so much.
"Given that my mama let us spend so much time with her, I think she also rather enjoyed watching those passions blossom. Those times together, those happy memories, have now become massively precious to each and every one of us."
Meanwhile, one of James' major interests was once revealed by the Queen herself several years ago as she talked proudly about the youngster.
During a ceremony in Windsor Castle in 2017, she was introduced to an eight-year-old boy, who was around the same age as James at the time.
She told him: "My grandson is nine and he does nothing else but tries to drive a car - mostly mine."
You can now buy Friday's historic Daily Mirror commemorating the death of the Queen here: mirror.co.uk/commemorative.
