While Louis sleeps on his mother's lap as Prince George, Prince William and Princess Charlotte sit alongside, the eye is immediately drawn to Kate's mother, Carole Middleton.
The 63-year-old has been positioned behind the children and wears a $2,443 powder blue silk crepe 1940s-inspired dress from Suzannah, with a matching hat.
She stands proudly behind her daughter with her husband Michael, 69, to her left.
Kate's sister Pippa, 34, now Mrs Matthews and expecting her own child, also stands behind the Chippendale sofa in a custom-made Alessandra Rich outfit that complements her mother's.
Her husband, multi-millionaire hedge fund manager James, whom she married last year, makes the family group, along with her bearded brother, also called James. The other half of the line-up includes the new Duchess of Sussex, the first time she has joined her husband's family for such an intimate portrait since her wedding to Prince Harry in May.
Meghan, 36, in an olive green Ralph Lauren outfit with a hat by Stephen Jones, stands next to a slightly serious-looking Harry.
The Duchess of Cornwall is cheerful in a cream Fiona Clare dress and a Locke hat, while grandfather Prince Charles appears tanned and relaxed.
On the sofa, William has a protective arm around George – who will be five next Sunday – while cheeky Charlotte stares challengingly at the camera as if plotting her next piece of mischief.
Two more images have also been released, seen on the next pages. One shows only members of the royal family, with Charlotte holding her baby brother's tiny hand. George is by now sitting on his father's lap and grinning happily at the camera, presumably at some behind-the-scenes antics.
The final image shows only the Cambridges, with Charlotte apparently playing peek-a-boo from underneath Louis's christening gown as Kate gazes at her baby son and a beaming William placing a comforting hand on a slightly hesitant George.
Mr Holyoak said: "Everyone was so relaxed and in such good spirits, it was an absolute pleasure. I only hope I have captured some of that joy in my photographs."
