After suffering a serious injury while working on the gallops at the weekend, the inevitable was confirmed today when ' The Best Flat Horse in the World ' was officially retired.
One of the most impressive winners of Ascot's King George VI and Queen Elizabeth Stakes, Harbinger, who didn't see the racecourse until making his debut as a 3 year-old, probably had more improvement to come and the sport eagerly anticipated the rest of his 4 year-old career.
Harry Herbert, issued a statement on behalf of the colt's owners, the Admiral Rous Syndicate saying: " It is with regret that it has been decided to retire Harbinger from racing.
We are pleased to report that thankfully the horse is recovering well. The decision to retire Harbinger is based on the welfare of the horse which is paramount to all concerned."
The son of Dansili was due to take in both the Juddmonte International at York next week before being trained for a crack at Europe's highlight, the Qatar Prix De L'Arc De Triomphe in October.
Sir Michael Stoute's charge had been a short price for both races with bookmakers, with trainer Aidan O'Brien now responsible for the new market leaders'.
Rip Van Winkle is clear favourite for York's International, with Ladbrokes, who offer a free £30 bet to new online customers, a standout 6/4.
Stablemate, and winner of yesterday's Royal Whip at the Curragh, Fame and Glory, is heading the " Arc " ante-post market at a top price 10/3 with William Hill, who also offer the same free bet to new customers.
While it is disappointing that horseracing enthusiasts will never know just how good Harbinger could have been but for the cruel finger of fate, the majestic performance that was his 2010 King George VI and Queen Elizabeth victory, will, for many, live long in the memory.