"He's old and she's pregnant," joked Harry when questioned about why his brother, Prince William, and sister-in-law, Kate, were not running the marathon as he had lightheartedly suggested they would at last year's race.
"What's fantastic is that my brother and his wife will be doing it next year, I think," the fun-loving Prince joked during the BBC's marathon coverage in 2012. "He's going to have to now, isn't he?" he added.
Harry, who is patron of the London Marathon Charitable Trust, was waiting at the finish line, ready to congratulate those who completed the race before proudly handing out their awards with Sir Richard Branson.
The Prince's appearance at the high-profile occasion was significant in light of the tragic events that occurred at the Boston Marathon earlier in the week. Bombs set off as triumphant competitors were crossing the finish line in the US city had raised security concerns at the London event, but the royal showed no sign of backing out of his duty.
Vowing to honour his long-standing commitment at the race, Harry led lead the country's show of solidarity in defiance of the blasts that took three lives and injured more than 170.
"As far as we are concerned," said a St James's Palace spokesman. "There's nothing to suggest any change," they added, confirming that Harry would still attend the long distance run.
As the race began runners and supporters alike observed a 30-second silence and participants. People were also encouraged to wear a black ribbon given to them when they picked up their race number as a show of unity with the victims of Monday's attack, which Harry wore on the left lapel of his jacket.