Princess Charlotte of Cambridge
The middle child and only daughter of the Duke and Duchess of Cambridge has made a name for herself for her royal confidence despite being just three years old.
It was Charlotte - Harry’s niece - who led the way into the Lindo Wing to meet new baby brother Prince Louis, giving a regal wave as she went.
Her parents have told how the fourth in line to the throne rules the roost, saying she is “very sweet” but also feisty.
Florence van Cutsem
Three-year-old Florence is Prince Harry’s goddaughter, and the daughter of his long-standing family friend Major Nicholas van Cutsem and Alice van Cutsem.
Major van Cutsem, a major with the Household Cavalry’s Life Guards, has been a friend of Harry and William’s since childhood.
Remi Litt is the six-year-old daughter of Ms Markle’s close friend Benita Litt and her husband Darren Litt.
Ms Markle is Remi’s godmother and in a since deleted Instagram post, the actress shared a picture of herself with the family - including her two “fairy god-daughters” - showing them happily posing in front of a Christmas tree after spending the holidays together in 2016.
Benita runs her own brand agency under her name where she helps others to start businesses.
Ms Markle’s other goddaughter is seven years old and Benita Litt’s oldest child.
Ivy is the four-year-old youngest child of Meghan’s stylist and best friend Jessica Mulroney.
The youngster’s name is actually Isabel Veronica but she is nicknamed Ivy.
Jessica Mulroney runs a bridal store in Toronto, where Meghan used to film Suits, and is said to have helped the bride choose her wedding gown.
She is married to Ben Mulroney - son of former Canadian prime minister Brian Mulroney.
Zalie is the youngest of the bridesmaids at just two years old.
She is another of Harry’s goddaughters and the daughter of one of his best friends, Jake Warren and Mr Warren’s wife Zoe.
The Warren family are closely connected to the royals through horse-racing. Jake’s father John Warren is the Queen’s racing manager.
The father-and-son team run Highclere Stud in Newbury together.
Prince George of Cambridge
Prince George, who is four, is third in line to the throne and a future king.
William and Kate’s eldest child is said to be shyer than his younger sister Charlotte, and the duke has told how his son loves helicopters, flying and is obsessed with all things police-related.
Like Charlotte, George is rarely seen in public. The duke and duchess try to ensure their children are protected from media intrusion.
But the pair have appeared at key royal events such as the annual Trooping the Colour parade, and have joined William and Kate on official overseas tours.
Six-year-old Jasper Dyer is also a godson of Harry’s and the son of his trusted mentor Mark Dyer and Mr Dyer’s wife Amanda.
Former Welsh Guards office Mr Dyer has been a key father figure to the prince since childhood.
A former equerry to the Prince of Wales, he was entrusted by Charles to keep an eye on Harry.
The pair travelled together in Harry’s gap year and he inspired the prince’s charity work in Lesotho, southern Africa, after arranging Harry’s first ever stay in the country.
Brian and John Mulroney
The fraternal twin sons of Jessica and Ben Mulroney are seven years old - and older siblings to Ivy Mulroney.
In an interview with thestar.com in 2014, Mrs Mulroney described how the boys were best friends.
“Ben was at the MMVAs (iHeartRadio Much Music Video Awards) and John did something really sweet,” she said. “He hugged Brian from behind and said, ‘Brian, you make me great’. “
The article described the children, who had two nannies, as “incredibly well-behaved”.