The London Marathon will see more than 40,000 runners take to the streets of the capital to run the 26.2-mile course on Sunday 23 April.
Before stepping back from royal duties in 2020, the Duke of Sussex was patron of the London Marathon Charitable Trust for nearly a decade.
Harry was one of the official starters of the 2017 marathon, alongside the then-Duke and Duchess of Cambridge, when the Royal Foundation's Heads Together campaign was the event's Charity of the Year.
The royal trio took part in a training session with runners in the lead-up to the London Marathon, where they went head-to-head during a relay race.
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© GettyWhile Harry has laid bare his complicated relationship with his family in recent years, he was often pictured making his sister-in-law Kate laugh during their joint engagements.
See William, Kate and Harry giggle and tease one another ahead of the race at Queen Elizabeth Olympic Park in the clip below. Can you guess who won?
When Harry was interviewed on the BBC back in 2012, he put his brother and sister-in-law forward to run the London Marathon the following year in 2013.
"What's fantastic is my brother and his wife will be doing it next year, I think," he quipped.
Interviewer Sue Barker replied: "You've just said that live on air," to which Harry said: "He's going to have to do it now, isn't he?"
Fans went wild at the prospect of Kate and William taking part in the race, but a spokesman clarified at the time that Harry's comments were "said in jest".
In 2010, Princess Beatrice became the first royal ever to complete the London Marathon, running the gruelling race in honour of the Children in Crisis charity.
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