Frankel's foal goes up for auction in just over an hour.
Together with his mother, Crystal Gaze, who is expecting a second foal by the undefeated Newmarket racehorse, he could fetch more than £1m at the auction at Kensington Palace.
Henry Beeby, chief executive at auctioneers Goffs, said: "Frankel was the greatest racehorse we had ever seen. He was undefeated. He was spectacular. And he was an absolute star.
"It's a bit like Usain Bolt turning up at stud."
Click below to hear more from Henry Beeby.
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More funnel clouds have been spotted spinning down from thunderstorm clouds across the Anglia region as the June summer soaking continues.
Some sunny spells for much of the day with scattered, locally heavy showers, mainly in the east. Cloud increasing from the west later.
Showers this evening, dying out overnight.