The royals may be the most famous and powerful family in the world - but most people don't know their surname.
When Meghan Markle married Prince Harry in May 2018, her last name officially became 'Mountbatten-Windsor'.
But the British royal family are very rarely referred to as their last name, with those who marry into the monarchy often still using their maiden name.
Kate married Prince William in 2011, but she is mainly described as Kate Middleton or her official royal title, Duchess of Cambridge.
Meghan Markle was granted the name Duchess of Sussex while her husband Harry is known as the Duke of Sussex.
What is the royal family's last name?
Because the royal family is so well known, they do not typically require a surname to be identified.
Before 1917, members of the British Royal Family had no surname at all, only the name of the house or dynasty to which they belonged.
However, the family name of Windsor was confirmed by Queen Elizabeth II after her accession to the throne in 1952.
Then in 1960, The Queen and Prince Philip wanted their own direct descendants to be distinguished from the rest of the royal Family, as Windsor is the surname used by all the male and unmarried female descendants of George V.
'It was declared in the Privy Council that the Queen's descendants, other than those with the style of Royal Highness and the title of Prince/Princess, or female descendants who marry, would carry the name of Mountbatten-Windsor,' the Royal Family website reads.
Mountbatten is Prince Philip's surname and the name first appeared on an official royal document on November 14 1973, when Princess Anne married Captain Mark Phillips.
Unless Prince Charles makes any changes when he becomes king, 'he will continue to be of the House of Windsor and his grandchildren will use the surname Mountbatten-Windsor', the website continues.
Prince William and Prince Harry were officially known as William Wales and Harry Wales when they were in the military, as their father Charles is the Prince of Wales.
Kate and William's children Prince George, Princess Charlotte and Prince Louis will be enrolled at school with the surname Cambridge, as their parents are the Duke and Duchess of Cambridge.
Any child of Meghan and Harry's is also likely to bear the surname Sussex in official terms.