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.
More top news
Any showers should die away this evening with most places dry overnight.
The veteran rockers Status Quo have been forced to postpone a concert in Norwich this weekend after frontman Francis Rossi became ill
Police are ramping up security at the British Grand Prix at Silverstone this year in the wake of a number of terror attacks.