This year, King Charles will have two birthdays for the first time in his life. The Trooping the Colour parade on June 17 is traditionally seen as the public birthday of the reigning monarch, though Charles was actually born on November 14.

King Charles will have two birthdays this year, a public one in June, and his actual birthday in November. He will participate in Trooping the Colour, riding on horseback for the first time in 30 years, but this could be a risk to his back, as he’s had past injuries from polo accidents.

The tradition dates back to King George II in 1748 and is a beloved royal event. King Charles, who is 74, will lead the parade, which includes over 1,400 soldiers, 400 horses, and 400 musicians.

His presence on horseback is a change from recent monarchs. King Charles has experienced back issues over the years, which could be aggravated by riding a horse.

His previous polo accidents have contributed to his back problems. King Charles has been dedicated to gardening but mentioned back pain while working on it. While the parade is an exciting event, it carries potential health risks for the King.