We’ve covered our pick of the greatest racehorses in history – horses with such character, perseverance and brilliance that they’ll forever be remembered by the racing fraternity.
However, horses that passed through their careers undefeated are a breed of their own.
Often competing in the highest levels of racing against champion racehorses, only a few dozen horses in the history of the sport have managed to win every race they have run.
Here’s our pick of the greatest unbeaten racehorses in history.
This Australian filly is easily the greatest sprint racehorse of all time, and a contender for the title of greatest racehorse of all time. Competing in highly competitive, unpredictable sprint races, she ran 25 races in the course of her career, winning all of them.
Her wins included 15 Group One victories. And her success was not limited to Australian courses. Black Caviar proved herself against international fields too, winning the Group 1 Diamond Jubilee Stakes at Royal Ascot in 2012.
Hungary is not a country renowned for its racing culture, however, in Kincsem it produced the most successful racehorse in the history of thoroughbred racing.
Over the course of four seasons in the late 1800s Kincsem raced in and won 54 races across the European continent.
Her feats included winning all of the Hungarian Classics in 1877, then conquering Europe with a win in England’s Goodwood Cup as well as high class Stakes races in France and Germany.
Eclipsed achieved his feats in the late 1700s, setting a record that has yet to be beaten by any British or Irish racehorse.
Notorious for his poor temperament, Eclipse was a formidable opponent on the racecourses, and won all of his 18 races, including 11 King’s Plates.
His legacy includes races named in honour of him in both France and England, as well as the phrase ‘Eclipse first and the rest nowhere’, which is now adapted to apply to any dominant victory.
Ribot lays claim to the second longest undefeated run of any British racehorse in history, unbeaten in his 16 race career.
Although he competed primarily in Italy during the 1950s, Ribot’s brilliance also secured him victories in major international races like the Prix de l’Arc de Triomphe and King George VI and Queen Elizabeth Stakes.
Following his retirement Ribot became an important sire, with his progeny claiming a host of the most important Group 1 races in both Europe and the United States.
Colin lays claim to being the greatest unbeaten Grade 1 race winner in the history of racing in the United States.
His 15 race career took place over the years 1907 and 1908, with the majority of his wins coming during his season as a 2-year-old.
However, he was also a force to be reckoned with as a 3-year-old, and his wins during his final season included taking the last leg of that year’s Triple Crown at the 1908 Belmont Stakes.
Arguably the greatest stallion of the modern racing era, Frankel ran and won 14 races over three seasons between 2010 and 2012, including 11 Group 1 wins.
His win in the 2,000 Guineas is regarded as the finest of his career, as he led the race from start to finish, opening a gap of 15 lengths by the halfway mark before easing home by 6 lengths.
By 2012 Frankel had received the highest racehorse rating in the history of Timeform, who assigned him a rating of 147.
Personal Ensign was an American mare who made her mark on racing in the United States during the 1980s, running 13 races without defeat.
Over the course of three seasons Personal Ensign won several Grade 1 victories, including a win against male horses in the prestigious Whitney Handicap.
Her most famous win was reserved for the 1988 Breeders Cup Distaff where she defeated Kentucky Derby winner, Winning Colors, to end her career unbeaten.
Peppers Pride is the most prolific winner among the unbeaten racehorses produced by the United States, and also holds the American record for an unbeaten streak.
Unbeaten in 19 races during her career, Peppers Pride never raced outside of her native state of New Mexico and was raced by the same jockey throughout her career.
Zarkava is the greatest filly produced by Ireland and the finest filly ever to compete in French thoroughbred racing.
Her pedigree was impeccable, with her lineage including a number of legendary racehorses, including Secretariat, Northern Dancer, Nijinksy and Mill Reef.
Zarkava ran just seven races from 2007 to 2008, winning all of them. Her victories included five Group 1 races, including the Prix de l’Arc de Triomphe.
Sired by legendary British racehorse, Flying Fox, Ajax is arguably the finest stallion to have competed in French thoroughbred racing.
All of Ajax’s wins were achieved in the year 1904, and included two of France’s most prestigious races at the time – the Prix du Jockey Club and the Grand Prix de Paris.
Ajax also proved to be an influential sire after his retirement, with his progeny including French Group 1 winner Teddy and the undefeated Havresac II.