The Queen is to be the official starter of the 2018 London Marathon.
Elizabeth II will push the start button from the grounds of Windsor Castle, beginning the race at 10am on Sunday, April 22.
The signal will be broadcast on big screens and see 40,000 runners set off from Blackheath to run the 26.2 miles to The Mall, in front of Buckingham Palace.
London Marathon Events Ltd chairman Sir John Spurling said: "We are deeply honoured that Her Majesty The Queen has accepted the invitation to start the 2018 LondonMarathon.
"Especially as this will happen 110 years after the 1908 Olympic Marathon was started at Windsor Castle by the then Princess Mary, grandmother to The Queen."
The 1908 Olympic event was the first marathon to be held over the now classic 26.2-mile distance.
Historians suggested the extra 385 yards were included either to finish the race in front of the Royal box at the White City Stadium, or to start the race in front of the Royal nursery at Windsor.