Prince Harry and Meghan Markle aren't the only ones who are involved in a row over their titles - as it's never been clear what their children will be called.
Archie and Lilibet were not given HRH titles at birth due to their position in the line of succession, but now formal discussions have taken place and a change has been made.
With the announcement that one-year-old Lilibet has been christened, a spokesperson for Harry and Meghan officially used the 'princess' title.
A royal source has now confirmed the King was notified of Harry and Meghan's intention to use the titled for their children, saying: "The appropriate conversations have taken place ahead of today's news (of Lilibet's christening)."
Whether the Duke and Duchess of Sussex's children receive titles has always been a major talking point, but has grown in interest since the death of Queen Elizabeth II.
When Lilibet was born in June 2021 she was the great-grandchildren of the Monarch, so wasn't eligible for a title just like her older brother and cousins.
However, the late Queen stepped in to change the rules for Prince George, Princess Charlotte and Prince Louis because Prince William and Kate Middleton's eldest will be king one day.
Because Harry is less senior than his brother, having famously referred to himself as the 'Spare', it didn't apply to his children.
However, Lilibet became entitled to become a princess when her grandfather King Charles acceded to the throne in September last year.
But Charles is understood to have long desired a stripped-back monarchy with a reduced number of working royals as well as royal titles, which means the Sussexes' kids titles have been up in the air.
Following the Queen's death, Prince William, Kate and their children's titles on the royal family's website were automatically updated to reflect their new titles - but there was no such change for Archie and Lilibet.
According to royal expert Roya Nikkha, King Charles had spoken to his son to ask what he wanted his children to be known as.
Discussing whether the Duke and Duchess of Sussex's children will be granted new titles following King Charles' accession to the throne, she told The Royal Beat: "On the death of the Queen, Harry's children, Archie and Lilibet, automatically as grandchildren of the sovereign, became HRH and Prince and Princess. So they've got that now, but they've not been updated on the royal website with their new titles. They are still 'Master and Miss'.
"William and Kate's new titles were instantly updated and it's my understanding that this was discussed with father and son when Harry was over here and [Charles] said, 'what do you want?', and [Harry] said, 'I'd like my children to be able to decide about their titles when they come of age, it's not my decision to make for them. And we can only do that if we keep the titles'.
"They have the titles now, but it's up to Charles whether he allows them to keep them, or whether he issues letters patent to remove them, and that is still unresolved."
Following the tradition established by King George V in 1917, Archie and Lilibet can technically be referred to as Prince Archie and Princess Lilibet – if they choose it.
Upon the death of the Queen, Archie and Lilibet traditionally would have been allowed to use their new titles but they are still listed as "Master Archie Mountbatten-Windsor" and "Miss Lilibet Mountbatten-Windsor" in the official line of succession.
There have reportedly been arguments behind-the-scenes over the issue, with a source telling The Sun, Harry and Meghan were not pleased about the apparent absence of titles.
The source said: "Harry and Meghan were worried about the security issue and being prince and princess brings them the right to have certain levels of royal security."
In their Oprah interview last year, Meghan said that the Royal Family discussed changing the protocol in order to keep Archie from acquiring the royal title.
During the tell-all interview she told Winfrey: "In those months, when I was pregnant, all around this same time, we had in tandem the conversation of he won't be given security, he won't be given a title, and also concerns and conversations about how dark his skin will be when he's born."
It was understood that Harry and Meghan did not want to deny their children their birth-right, but let them decide themselves once they were old enough.
In October, it was reported that King Charles could gift his grandchildren titles, but not without a caveat.
Katie Nicholl, who published The New Royals, said that Charles could "insist" that any titles given would come with strings attached to try and keep the California-based pair in check, reports the Express.
Ms Nicholl told Palace Confidential podcast: "But if that did happen, it is going to come with a caveat.
"He is going to insist that Harry and Meghan are respectful of the institution if they are taking the titles of the institution. That is very important to him."
She said that "titles matter to Charles" and the new monarch will not hand them out freely.
Speculation has risen that Charles could follow the model laid out by Denmark's Queen Margrethe, who recently stripped her grandchildren of their royal duties and titles.
The royal author claimed constitutional experts, "who I spoke to for this book, the likes of Peter Hennessy and Doctor Ed Owens" all saw "this pattern of the British monarchy moving into a sort of European-style royalty".
Ms Nicholl added: "And if that is the case, then possibly they're not going to get these titles."
The discussion surrounding Lilibet's title has been reignited after Harry and Meghan announced she had been christened.
The one-year-old is said to have been christened last Friday at her home in Montecito, California, in front of 20 to 30 people, including godfather Tyler Perry and grandmother Doria Ragland.
A spokesperson for Harry and Meghan said: "I can confirm that Princess Lilibet Diana was christened on Friday, March 3 by the Archbishop of Los Angeles, the Rev John Taylor."
However, a source told PEOPLE magazine there were no royals in attendance at the ceremony, where attendees were treated to an afternoon of food and dancing.
Archie was seen dancing with his sister and godfather Perry flew in a 10-person gospel choir from Atlanta to sing at the event
The American actor and producer revealed he had been asked to be Lilibet's godfather during Meghan and Harry's Netflix series, which was released in December.
"I take a minute to take that in, and I thought I'd be honoured. I'd absolutely be honoured," he said.
"And I got off the phone, took it all in, then I called them back, I go ‘Ah hold on a second, does this mean we got to go over there and do all of that in the church with them and figure all that out, because I don’t want to do that.
"Maybe we can do a little private ceremony here and let that be that and if you have to do it there then it's OK."
