As Kate shares sweet nickname for Prince Louis, what do the royals call each other?
Watch: Princess of Wales calls Prince Louis by his nickname
They might have their own rather official titles, but there are some surprising Royal Family nicknames that have come to light over the years.
Everyone from the late Queen Elizabeth and Prince Philip, to King Charles and the Queen, have been revealed to enjoy some rather sweet – if unusual – monikers among themselves.
Over the coronation weekend, a video caught the sweet nickname that the Princess of Wales uses for her youngest son, Prince Louis.
The Wales family got stuck in at a local Scout group as part of the Big Help Out initiative on Monday as the royal children visited the group's scout hut in Slough.
While roasting marshmallows with her youngest child, the Princess of Wales was caught on video calling Prince Louis by his cute nickname, 'Lou Bug'.
“Pop that in the fire, Lou Bug,” Kate, 41, instructed, later dropping the pet name again as he took charge of a wheelbarrow.
“Well done, good job Lou Bug!” she said as her youngest wheeled the dirt around.
Lou Bug isn't the only nickname that the Prince and Princess of Wales have for their children. Kate and William, 40, often call Princess Charlotte, Lottie, or Mignonette, too.
From the late Queen Elizabeth's several nicknames – including the affectionate 'cabbage' – to Princess Diana's nickname for Prince William, see all the unusual monikers used in the Royal Family.
It was revealed over the coronation weekend that the Prince and Princess of Wales have a sweet nickname for their youngest child, Prince Louis.
Kate was caught twice on video whilst the family volunteered at a local Scout group as part of the Big Help Out calling her son Lou Bug.
Willy and Harold
Prince Harry's memoir revealed that he and his brother Prince William refer to one another as 'Willy' and 'Harold'.
The monikers are present in at least two parts of the book, according to The Telegraph, with the first during a physical row between the pair in 2019.
When the Duke of Sussex tried to calm the now-Prince of Wales, he recalled telling his older sibling: "Willy, I can’t speak to you when you’re like this.”
The latter replied: "I didn’t attack you, Harold.”
Read more: 7 jaw-dropping revelations from Prince Harry's memoir
In the second mention, Harry claimed to have asked his brother and then-girlfriend Kate Middleton – now the Princess of Wales – for their advice on a costume for a fancy dress party in 2005.
Revealing the options, which included a pilot uniform, he said: "I phoned Willy and Kate, asked what they thought. Nazi uniform, they said.
“They both howled. Worse than Willy’s leotard outfit! Way more ridiculous! Which, again, was the point.”
H, Haz, M and Meg
Late last year, viewers of the Duke and Duchess of Sussex's Netflix docuseries discovered their preference for calling one another 'H' and 'M'.
This wasn't the first time it emerged – in an interview in 2019, Meghan revealed to ITV's Tom Bradby that she called him 'H'.
However, sometimes she uses 'Haz' instead. In 2021, as the prince toured LA with James Corden, she referred to him in this way.
Meghan is often referred to as Meg by friends, as was revealed in the Netflix episodes.
As a child, the late Queen, then Princess Elizabeth, is said to have been unable to pronounce her own name well, instead saying 'Lilibet'.
The adorable mispronunciation became a nickname which was first used by her grandfather, King George V.
It stuck with the rest of her family too, and then became the name by which husband Prince Philip referred to her.
Harry and Meghan chose to name their daughter Lilibet Diana after she was born in 2021, and said the decision was made with the Queen's support.
Gary, or Gan-Gan
The late Queen, of course, had many an official royal title, but it was a different story at home.
According to royal correspondent Richard Kay, Prince William was encouraged to call her Granny as a child, but he couldn't quite get the hang of it. What he could manage, was Gary.
Kay said: "On another occasion, the Queen was on hand after William fell over at Buckingham Palace, bawling: ‘Gary, Gary’. A guest who went to help asked who Gary was, assuming it must be a member of the royal household.
"‘I’m Gary,’ explained the Queen, as she scooped him up. ‘He hasn’t learned to say Granny yet.’"
He doesn't still call her Gary, but his children had similar problems with working out what to call her.
The Princess of Wales has previously revealed when Prince George was a toddler he called her Gan-Gan.
Another one for the Queen, used by her late husband Prince Philip.
It was reported in 2006 in The Sunday Times that the Duke of Edinburgh had referred to his wife as 'cabbage'.
The nickname was used in the Peter Morgan film The Queen, which was released the same year.
Morgan said: "I inquired in royal circles and was told on very good authority that that is what the duke sometimes calls the Queen."
Not quite a nickname, but it seems King Charles is generally known as Papa to his sons and in-laws.
Prince Harry has referred to his father as Papa in speeches in the past, and on arrival at a join engagement in Cornwall in June 2021, it was easy to spot the moment the then-Duchess of Cambridge used the same name for him.
Usually, in public, the royals refer to one another by their titles or by their full names, but the duchess looked to be overcome with excitement at seeing her father-in-law before the true formalities of the evening began.
The name has been passed down the generations too, as a Mother's Day card shared by Kensington Palace on Instagram in March 2021 showed that Princess Charlotte calls Prince William 'Papa' too.
Fred and Gladys
These nicknames, used by King Charles and Queen Camilla for each other, were a big part of The Crown, season four, on Netflix.
The monikers were apparently first used by them when they dated briefly in their twenties.
But when Charles was set to marry Diana, he is said to have given Camilla a bracelet with 'GF' engraved on it, meaning Gladys and Fred.
Princess Eugenie and Princess Beatrice are very close.
The former often shares touching messages to her older sister Beatrice on Instagram around birthdays or when the royal has big news.
She uses 'Bea' or 'Beabea' when referring to her big sister, and often accompanies it with an emoji, of a bee, of course.
Meanwhile, Beatrice is less open on her social media, so we may never know how she refers to her little sister.
Lottie, or Mignonette
Princess Charlotte is already racking up royal nicknames from her parents.
Her mother, the Princess of Wales, was overheard referring to her daughter as 'Lottie' while on an engagement in Northern Ireland. She has also been heard calling her daughter 'poppet'.
But the grandest nickname comes from her father who calls her 'Mignonette'.
In a video of the family-of-five playing in the duchess' Chelsea Flower Show garden, he was heard calling "Mignonette", which Charlotte responded to with a "Yeah?"
It might come from the French word Mignon which means small and delicate.
PG or Tips
According to Vanity Fair, Prince George was referred to by his initials, PG, at his previous school: Thomas's, Battersea.
It was then revealed that his parents had decided to play with this and called him PG Tips, after the tea brand, or just 'Tips'.
While many people still refer to the Princess of Wales as Kate, apparently her brother-in-law Prince Harry decided he wanted his own name for her.
The prince was reported to have started calling her Cath, an alternative shortening of Catherine.
She was quizzed about it in 2017 during an interview on BBC Radio 1. Presenter Scott Mills put the nickname to her – and while she did not confirm it, she also didn't deny it.
"I’m not sure, I’m not that familiar with it," the then-duchess told the broadcaster. "I'll answer to most things though."
Read more: Did Prince Harry write the book himself?
Prince Charles started calling the Duchess of Sussex 'Tungsten' in her early royal days, according to the Daily Mail.
A source said: "Prince Charles admires Meghan for her strength and the backbone she gives Harry, who needs a tungsten-type figure in his life as he can be a bit of a softy. It’s become a term of endearment."
The nickname came because he saw her as strong and unbending, like the rare metal, apparently.
Talking of the Duchess of Sussex, her mother Doria Ragland has her own adorable nickname for her daughter that has stuck since childhood.
According to the Express, the duchess revealed on her now-closed blog The Tig – prior to joining the Royal Family – that she calls her 'Flower'.
Then, during an episode of her Spotify podcast Archetypes in November 2022, she shared: “My mom still calls me Flower. I'll be a 41-year-old Flower. That's fine.”
One of the most famous royal nicknames belongs to Sarah Ferguson, who has been known as Fergie for years.
Even as the Duchess of York, the title she was given when she married Prince Andrew, she has more commonly been known as Fergie.
It was also revealed to be a family nickname when Meghan used it during her interview with Oprah Winfrey in 2021.
Recalling learning how to curtsy before having a meal with the Yorks and the Queen, she said: "Right in front of the house we practiced and ran in. Fergie ran out and said, 'Do you know how to curtsy?'
"Apparently I did a very deep curtsy, I don’t remember it, and then we sat there and we chatted."
Princess Diana called her oldest son Wombat, according to Prince William himself.
He confessed to the nickname from his late mum in 2007 when he was interviewed by NBC.
The prince said: "It began when I was two. I've been rightfully told because I can't remember back that far.
"But when we went to Australia with our parents, and the wombat, you know, that's the local animal. So I just basically got called that. Not because I look like a wombat, or maybe I do."
Showing that sometimes a general term of affection is all that's needed, the Princess of Wales reportedly once called her husband 'babe' in public.
While the couple were at the Chelsea Flower Show in 2016, Prince William was asking about a Buxus plant, to which the princess is said to have told him: "Babe, we've got those. We've got loads of those."
Watch: Princess of Wales addressed King Charles using his unofficial title during the G7 Summit