King Charles III celebrates 75th birthday - why does he have two birthdays?

Happy birthday King Charles!

King Charles III is celebrating his 75th birthday today - but did you know, the monarch actually celebrates two birthdays?

The King has two birthdays - the first is in November, as he was born on 14 November 1948.

Then a second one - an official celebration - falls on the second Saturday of June called Trooping the Colour, which has marked the official birthday of the British monarch for over 260 years.

But why does the King have two birthdays, and how does he celebrate them? Find out below...

How is King Charles III celebrating his 75th birthday?

The King was presented with a birthday cake at a special charity get-together.

King Charles is celebrating his 75th birthday with the launch of his Coronation Food Project to help people facing food poverty.

Speaking about the project to the Big Issue magazine, the King said: "Food need is as real and urgent a problem as food waste." and said that "cost-of-living pressures" were resulting in "too many families and individuals missing out on nutritious meals".

The project aims to create food hubs that will give out food that would usually go to waste.

This photo shows King Charles playing with his mother Queen Elizabeth II's necklance as a baby in 1948.

He took inspiration for the project from his own birth celebrations.

His mother Queen Elizabeth II celebrated his birth in 1948 by donating food parcels to every family who had a child on the same day. After WWII there was still food-rationing - limits on certain foods to make sure there was enough to go round.

The King's birthday will also be celebrated with ceremonial gun salutes including at the Tower of London, a reception for NHS nurses and midwives, as well as a private dinner with close family and friends.

Where did the idea for two birthdays come from?

King Charles (far left) with his father The Duke of Edinburgh, his baby sister Princess Anne, and his Mother Queen Elizabeth in 1951

In the past, official celebrations to mark a King or Queen's birthday in the UK have been held on a day that isn't their actual birthday.

The Queen's great-grandfather, Edward VII, who was King from 1901 to 1910 was born in November, which is not known in the UK for its good weather.

But he wanted it to be possible to have a big public celebration outdoors - and November is quite cold and rainy.

So, given that his actual birthday wouldn't be a good time of year for a big birthday parade, he decided to combine it with an annual military parade in the summer, when the weather would hopefully be nicer.

What is Trooping the Colour?

The Trooping the Colour parade is quite a spectacle!

Trooping the Colour has marked the official birthday of the British King or Queen for more than 260 years.

It's also known as The King's Birthday Parade.

More than 1400 soldiers, 200 horses and 400 musicians usually take part in the event, so it's quite a spectacle!

Lots of members of the public waving flags and wearing Union Jacks normally fill the Mall outside Buckingham Palace to watch it.

King Charles III celebrated his first Trooping the Colour parade as King this year in June.

On the day, normally a big parade starts at the King's official residence - Buckingham Palace - before moving along the Mall to Horse Guards Parade at Whitehall, near to Downing Street, and then back again.

Then it's traditional for the royal family to travel down the Mall as part of the ceremony, and gather on Buckingham Palace's balcony to greet well-wishers and watch RAF planes perform an aerial display for the occasion.