King Charles III will recognise his official birthday this weekend, with the annual Trooping the Colour ceremony taking place to mark the monarch's summer celebration.
Following a tradition set by his great-great-grandfather, Edward VII, the British sovereign has two birthdays - their actual birthday, and an official celebration in June.
Ahead of the event on Saturday 17th June, which will include a full parade as well as the iconic fly-past by the Royal Air Force, the Prince of Wales reviewed troops on horseback last weekend.
It is the first time that Prince William has lead The Colonel's Review, which took place in St James's Park, London on Saturday amidst a sudden heatwave in the UK.
While William attended on horseback for the ceremony, which sees hundreds of horses and guardsmen gather to display complex battlefield drill manoeuvres, thousands gathered in the capital to witness the military parade.
However the temperature began to rise and reached around 28 degrees celsius, leading to three soldiers collapsing in the heat. They were consequently taken away on stretchers.
Two more guardsmen were helped to their feet after suffering in the heat, with one receiving an applause when he regained himself although he departed with medical staff.
The youngest among them, 18 year old James Calford from Cardiff, Wales, explained that the event is 'like being stood in a sauna with a 200kg dumbbell in your left hand' adding that it 'is a lot harder than it looks on the TV'.
He said: "Once you have got your tunic and bearskin on and carrying your rifle in heat it is incredibly uncomfortable."
Prince William has since responded, and shared his thanks to everyone involved in the day.
Taking to Twitter via The Prince and Princess of Wales' official account, he wrote: "A big thank you to every soldier who took part in the Colonel’s Review this morning in the heat. Difficult conditions but you all did a really good job. Thank you. W."
