Now, the late monarch's family has expanded further, as Princess Eugenie welcomed her second child - Ernest George Ronnie Brooksbank - with husband Jack Brooksbank on 30 May, 2023.
He was born without a title, as it is usual for monarchy members to take varying titles, or none at all.
Queen Elizabeth II's grandchildren
Peter Phillips - born 15 November, 1977
Peter Phillips is the eldest and only son of Anne, the Princess Royal, and her former husband Captain Mark Phillips. He was late Queen's first grandchild but Anne opted not to give him a royal title.
Despite being fifth in line to the throne when he was born, he is not known as His Royal Highness. He is currently 18th in the line of succession.
Phillips isn't a working royal. He doesn't carry out any official royal duties, but is still invited to Royal Family events. He is currently managing director at SEL UK, a boutique sports management firm.
He met Autumn Kelly in 2003, and the couple married in Windsor in 2008, but later divorced in 2021. They have two children, Savannah and Isla.
Phillips is currently dating Lindsay Wallace, and brought her to the King's coronation concert in May 2023.
Zara Tindall (née Phillips) - born 15 May, 1981
Zara Tindall is the second child, and only daughter, of Princess Anne and Captain Phillips. She is the younger sister of Peter Phillips.
She was also not given a title, meaning she is not an HRH, and a non-working royal, but makes public appearances from time to time.
Tindall is an accomplished equestrian, competing at the London Olympics in 2012, and winning BBC Sports Personality of the Year in 2010.
Tindall married former England rugby player Mike Tindall in 2011. The couple have three children, Mia, Lena and Lucas.
Prince William - born 21 June, 1982
First in line to the throne, Prince William is the eldest son of King Charles III and the late Diana, Princess of Wales.
William went to Eton College in Windsor, and St Andrews for university after a gap year, where he met his now-wife, Kate Middleton.
William and Kate announced their engagement in November 2010, and married at Westminster Abbey in April 2011.
The couple have three children – Prince George, Princess Charlotte and Prince Louis – and are both working royals.
Prince Harry - born 15 September, 1984
William's younger brother, Prince Harry (real name Henry) is the second son of Charles and Diana.
The Duke of Sussex also went to Eton College, before taking a gap year and starting his military career at Sandhurst. He served in the army for 10 years, including a tour in Afghanistan.
He met Meghan Markle in early 2016. The couple married at St George's Chapel, Windsor in May 2018. They have a son, Prince Archie, and a daughter, Princess Lili.
In January 2020, they announced their decision to step back as senior members of the Royal Family. They have since moved to California where they live in Montecito, Santa Barbara.
Princess Beatrice - born 8 August, 1988
Princess Beatrice is the oldest daughter of the late Queen's second son, Prince Andrew, and his former wife Sarah Ferguson.
Although she has a royal title, Princess Beatrice is not a working royal, but is a patron of several charities and organisations. She is currently vice president of partnerships and strategy at Afiniti, a software company.
Princess Beatrice announced her engagement to property developer Edoardo Mapelli Mozzi in September 2019, and married in secret in July 2020 due to the COVID-19 pandemic. The couple welcomed their first child, a daughter named Sienna, in 2021.
Princess Eugenie - born 23 March, 1990
The second daughter of Andrew and Sarah, Princess Eugenie suffered scoliosis as a child and had to undergo surgery to correct the curvature of her spine.
Like her sister, she attends events as a member of the Royal Family but is not a working royal. She has worked as a director of Hauser & Wirth art gallery since 2015.
Princess Eugenie married Jack Brooksbank in October 2018 in Windsor, and chose a dress to show her scoliosis scar. The couple welcomed their first child, August, in February 2021, and their second, Ernest, in May 2023.
Lady Louise Windsor - born 8 November, 2003
Lady Louise Windsor is the Queen's youngest granddaughter and the firstborn child of Prince Edward and his wife Sophie.
She was born prematurely in November 2003, while her father was away, and was the last royal baby to wear the original christening gown when she was baptised in 2004.
Louise was born with an eye condition which causes one eye to turn inwards. She had an unsuccessful operation to correct it, but treatment in 2013 restored her sight.
She is largely out of the public eye at the moment, studying at St Andrews university, but appears at big Royal Family events.
James, Earl of Wessex - born 17 December, 2007
James is the late Queen's youngest grandchild, and Prince Edward and Sophie's only son.
Like his sister, he has a courtesy title, and was known as Viscount Severn until March 2023, when he inherited the Earl of Wessex title from his father upon his parents becoming the Duke and Duchess of Edinburgh.
James lives in Bagshot Park, in Surrey, with his family, and occasionally attends larger Royal Family events, such as the coronation, when his schooling allows.
Who are Queen Elizabeth II's great-grandchildren?
Savannah Phillips - born 29 December, 2010
Savannah Anne Kathleen Phillips is the oldest daughter of Peter Phillips and his former wife Autumn Kelly, and the late Queen's first great-grandchild. Anne is a nod to her grandmother, Princess Anne.
Savannah does not have a royal title, and will not carry out royal duties, but attends larger Royal Family events such as weddings and Trooping the Colour.
Savannah and her family live on her grandmother's Gatcombe Park Estate, near Windsor.
Isla Phillips - born 29 March, 2012
Isla Elizabeth Phillips is the second daughter of Peter and Autumn Phillips and the younger sister of Savannah. Her middle name, Elizabeth, is after her great-grandmother, the Queen.
Isla also has no royal title and remains out of the public eye, save for larger Royal Family events such as the Platinum Jubilee in 2022.
Mia Tindall - born 17 January, 2014
Mia Grace Tindall is the oldest daughter of Zara and Mike Tindall. She was born in January 2014, and her father announced her name on Twitter.
The Tindalls also have a home on Princess Anne's Gatcombe Park Estate, where Mia and her family live.
She is seen at general Royal Family events like Trooping the Colour and the events on Gatcombe Park estate.
Lena Tindall - born June, 2018
Lena Elizabeth Tindall is the second daughter of Zara and Mike Tindall. She was born in 2018, after the couple had suffered a miscarriage.
She also doesn't have a royal title and is unlikely to ever be a working royal, but occasionally appears at some of the larger Royal Family events.
Lucas Philip Tindall - born March, 2021
Lucas Philip Tindall was born on the bathroom floor of the family home in Gloucestershire, following a night of contractions for mum Zara.
He is the first son for the Tindalls, the first grandson for Princess Anne, and also doesn't have a royal title,
Prince George of Wales - born 22 July, 2013
Second in line to the throne, George Alexander Louis is the oldest son, and first child of the Prince and Princess of Wales.
He attends Lambrook School in Berkshire, after the Wales family moved to Windsor in 2022.
He has accompanied his parents on a number of their tours abroad and began making public appearances with his parents in summer 2022 for the late Queen's Platinum Jubilee celebrations.
Prince George played an important role as a page at the coronation of his grandfather, King Charles, in 2023.
Princess Charlotte of Wales - born 2 May, 2015
Charlotte Elizabeth Diana is the second child, and only daughter of the Prince and Princess of Wales. Her name is a nod to her grandfather, Prince Charles, her great-grandmother, Queen Elizabeth II, and her late grandmother, Diana, Princess of Wales.
Charlotte attends Lambrook School with her older brother and is fourth in line to the throne.
Charlotte has also been on royal tours with her parents and as with her brother began making public appearances with them in the summer of 2022.
Prince Louis of Wales - born 23 April, 2018
Louis Arthur Charles is the third child of William and Kate and is fifth in line to the throne.
Louis is the first younger brother of an older sister not to displace her in the line of succession, thanks to a change in the law which came into effect in 2013. Charlotte will retain her place as fourth in line despite Louis being a boy, and her children will be above him and his children.
Louis also attends Lambrook School. He has made public appearances on the balcony at Buckingham Palace as well as during the Platinum Jubilee in 2022 and King's coronation in 2023.
Prince Archie of Sussex - born 6 May, 2019
Archie Harrison Mountbatten-Windsor is the first child of Prince Harry and Meghan Markle. Though Archie is seventh in line to the throne, his parents chose not to use a royal title at birth.
However, on the ascension of his grandfather Charles to the throne, as the children of a son of a sovereign, Archie and his sister automatically became prince and a princess, according to the rules set out by King George V in 1917. They can now have the HRH style if they choose to use it, too.
Archie has been brought up away from the public eye, with his christening held in private and names of his godparents not officially released, although he made brief appearances on Meghan's Archewell Audio podcast and his parents' Netflix documentary, Harry & Meghan.
Princess Lilbet of Sussex - born 4 June, 2021
Harry and Meghan announced the birth of their second child, Lilibet 'Lili' Diana Mountbatten-Windsor in June 2021, named after her great-grandmother, Queen Elizabeth, whose family nickname was Lilibet, and her paternal grandmother, the late Diana, Princess of Wales.
It was first reported that Lili would use the princess style after her christening in California.
Sienna Elizabeth Mapelli Mozzi - born 19 September, 2021
Sienna Elizabeth Mapelli Mozzi, Princess Beatrice and her husband Edoardo Mapelli Mozzi's first child, was born in the same year as her cousin August.
Sienna doesn't have a royal style, but middle name was a nod to her great grandmother Queen Elizabeth.
She currently stands at 10th in line to the throne.
August Brooksbank - born 21 February, 2021
August Philip Hawke Brooksbank is the first son of Princess Eugenie and Jack Brooksbank, born at Portland Hospital in London, the same hospital where Eugenie was born.
He is named after his great-grandfather, Prince Philip, and his two great x5 grandfathers, a Brooksbank family ancestor and Prince Albert, whose middle name was Augustus. He doesn't have a royal title.
Ernest Brooksbank - born 30 May, 2023
Ernest George Ronnie Brooksbank is the second son of Princess Eugenie and her husband Jack Brooksbank, and is currently the youngest member of the Royal Family, although he doesn't have a royal title.
Eugenie named him after his great great great grandfather George, Britain's King George V (born George Frederick Ernest Albert, and the late Queen Elizabeth's own grandfather), and his paternal "Grandpa George" (Jack Brooksbank's father), as well as Eugenie's maternal grandfather, Ronald.
This article was updated on 6 June, 2023.