Why does King Charles III get two birthdays? The Trooping the Colour parade, explained

Wait, does King Charles III have two birthdays?

Royal family watchers may be scratching their heads at headlines saying the recently crowned monarch will celebrate his 75th birthday this Saturday, even though his birthday falls on Nov. 14.

It's a long-held royal tradition for British monarchs to celebrate their day of birth in an annual summer parade known as Trooping the Colour. This year's occasion will include 1,400 parading soldiers, 200 horses and 400 musicians for a "great display of military precision, horsemanship and fanfare," according to the royal family's official website.

What is the Trooping the Colour parade and what is its significance? Here's what to know.

How did Trooping the Colour come to be?

The Trooping the Colour parade has marked the official birthday of Britain's sovereign for 260 years, with the parade designated as the official marker for the sovereign's birthday in 1748.

The "Colours" in the title of the parade refer to the regimental flags and insignia displayed by British soldiers in order to provide a rallying point on the battlefield. "This was important because, without modern communications, it was all too easy for troops to become disoriented and separated from their unit during conflict," reads the website for The Household Division, a unit of the British military, adding that young officers would march between ranks of troops with the colors held high in order to let soldiers know what their regiment's colors looked like.

This march is the origin of the word "trooping."

"So, what today is a great tradition began life as a vital and practical parade designed to aid unit recognition before a battle commenced," The Household Division website adds.

Why is Trooping the Colour the monarch's official birthday?

Who doesn't love a summertime birthday? The tradition of using the parade as the monarch's official birthday is said to date back to King George II's reign in 1748, according to the British Army website and the Royal Museums Greenwich.

Like Charles, George II's birthday was in November. The former monarch determined that the winter was too cold for a birthday parade so he grouped it with the annual Trooping the Color parade that was traditionally in the summer, per the Royal Museums Greenwich.

What will happen at this year's Trooping the Colour parade?

Charles is expected to ride horseback during the parade, marking the first time a reigning British monarch has done that for Trooping the Colour since 1986, according to Buckingham Palace. His late mother Queen Elizabeth II was monarch at the time.

Charles' parade begins at Buckingham Palace, and he will travel down The Mall to receive the Royal Solute.

The monarch will later be joined by Queen Consort Camilla and other members of the royal family to watch the 1st Battalion Welsh Guards Troop their Colour and watch a military fly past from the balcony at Buckingham Palace.

'Difficult conditions': Prince William thanks soldiers after 3 faint during salute rehearsal

What happened at last year's Trooping the Colour?

Last year, the Trooping the Colour parade saw Queen Elizabeth II appear – twice – for the first time in years on the balcony of Buckingham Palace.

Dressed in a pale blue coat dress and hat, holding a cane and wearing shaded glasses, the queen looked happy and well, and even chatted to one of her great-grandchildren as she stood on the balcony.

She appeared first with one of her royal cousins, the Duke of Kent, to take the salute of her troops, and then with her extended family of "working royals" as 70 RAF jets roared overhead in the traditional end of the Trooping parade.

Fighter jets flew in formation to create the number "70" in the sky over the palace, acknowledging the queen's unprecedented 70 years on her throne.

Also for the first time, the queen "took the salute" from the balcony as ranks of scarlet-clad mounted and marching British soldiers passed below and huge crowds of people on The Mall shouted and cheered their affection for their long-serving "Platinum Queen."

More: Everything that happened at Charles III coronation: King and Camilla crowned, celebration

Contributing: Maria Puente, USA TODAY; The Associated Press

This article originally appeared on USA TODAY: What is Trooping the Colour? King Charles III's birthday, explained