Prince William and his eldest son, Prince George, are next in the line of succession after Prince Charles.
There’s been much speculation in recent months about what changes could come into force with a new monarchy – led by a King rather than a Queen.
Prince Charles has announced plans for a slimmed down monarchy when he takes the throne – which could see some senior royals weaned off public money.
Little is known about what a monarchy led by William will look like – despite the polls suggesting the public thinks he should take the throne before his father.
Meanwhile Prince George is only seven years old, but he will soon have to step up, just like his father did, to become a working royal.
Although Prince William and his son have limited powers, they both might one day have the authority to change some long standing royal traditions, which come with taking the throne.
And this might include changing one of the Queen’s well-known birthday celebrations.
Her Majesty has two birthdays, her actual birthday and an official public holiday.
The nation celebrated the Queen’s official birthday over the weekend with Trooping the Colour, which is the traditional parade for the Queen’s birthday in Britain.
The Queen’s actual birthday is in April, but during her reign, she has often publicly celebrated her birthday on the second weekend in June.
She is usually joined by her extended family for the event, which is marked with a flypast from the Royal Air Force’s Red Arrows.
But the tradition of celebrating the monarch’s birthday is June was not actually started by the Queen, as Express.co.uk explains.
For many years, the British monarch has opted to have two birthdays, with their official birthday held in the summer.
King Edward VII had a birthday which fell in November – a time known for bad weather in Britain. As a result, he opted to publicly celebrate his birthday in the summer instead.
It was a similar picture for King George VI, the Queen’s father.
The Queen has continued the tradition during her reign, and it is likely to be continued by her son, Prince Charles, as his birthday falls in November.
But Prince William and George could decide to forego the traditional two birthdays, as both their birthdays fall in the summer.
Prince William turns 39 on June 21, and Prince George turns eight on July 22.
As a result, their actual birthdays would likely coincide with good weather, negating the need for two birthday celebrations so close together.
As his birthday is in July though, George may decide to go one step further and alter the Queen’s traditional date in June for Trooping the Colour.
He may instead move the celebration to July to coincide with his actual birthday.