Bred in Ireland, Circus Maximus has deep American roots on his dam's side as he is a scion of the family of the fabulous La Troienne, by far the most influential matriarch of American Thoroughbred breeding in the 20th century. His descent traces though Lady Winborne, who raced only twice but, like her great-great-granddam, proved far more important in the paddocks than on the track.
A Secretariat half sister to the great Allez France, Lady Winborne was Group III-placed in Ireland as a 3-year-old and was initially mated to 1978 Wood Memorial Stakes (USA-I) winner Believe It as a 4-year-old. The resulting foal, Al Mamoon, proved an excellent kickoff to her broodmare career as he won five graded stakes including the 1987 John Henry Handicap (USA-IT).
Following Al Mamoon, Lady Winborne produced five other stakes winners from her 15 named foals. The best of the bunch was La Gueriere, a 1988 daughter of Lord At War who won the 1991 Queen Elizabeth II Invitational Challenge Cup Stakes (USA-IT). La Gueriere followed up on her racetrack success by producing 2009 Personal Ensign Stakes (USA-I) winner Icon Project (a daughter of Empire Maker who is, in turn, the dam of Grade II winner Fashion Business, by Frankel) and 1997 Oak Tree Derby (USA-IIT) winner Lasting Approval (by With Approval). Through her unraced Holy Bull daughter La Comete, La Gueriere is also the second dam of multiple Grade II winner and successful sire Munnings (by Speightstown).
La Gueriere is one of five stakes producers among Lady Winborne's daughters and is one of three with Grade or Group I winners among their descendants. Another to achieve that distinction, Lady Lady (by Little Current) produced stakes winner Lovat's Lady (by Lord At War) and is the third dam of three graded or Group stakes winners, headed by 2015 VRC Sprint Handicap (AUS-I) winner Delectation.
Circus Maximus traces to the third of those daughters, Benguela (by Little Current), who did not herself produce any stakes winners but is the dam of Catumbella (by Diesis), dam of 2003 Woodford Reserve Turf Classic Stakes (USA-IT) winner Honor in War (by Lord At War), a horse who was also a Group II winner in Australia as a 9-year-old. Another daughter of Benguela, Lady Angola (by Lord At War) produced multiple Group stakes winner Duntle (by Danehill Dancer), whose only foal is Circus Maximus.
Lady Winborne's family has repeatedly scored its greatest successes at 9 furlongs or less, which may help explain why a son of Galileo failed to stay out the 12 furlongs of the Derby stakes (though the influence of the speedy and precocious Danehill Dancer also cannot be discounted). On rain-softened going at Ascot, however, Circus Maximus had both the foot and the stamina to beat off more-fancied rivals, and the 10-furlong Eclipse Stakes (ENG-I) on July 6 has been mentioned as a possible next outing. Regardless of how he fares in the future, however, he was good enough to be a star on one of the world's biggest stages, reflecting great credit on a lady whose antecedents were royal indeed.