Mundig was unraced as a two-year-old, but his performances in home exercise gallops and private trial races made him a fancy for the Derby.
He was the subject of heavy betting by the Scott family and by  Bowes, although a great deal of secrecy surrounded his form, making him a very "dark horse".
 In April, Scott discovered that one of his stable lads had been passing information to bookmakers.
Rather than expose and dismiss the lad, Scott fed him false information, to the effect that the colt would not run at Epsom.
Mundig's odds lengthened and his connections were able to back him at 50/1.

Ridden by Bill Scott, the brother of his trainer, Mundig started at odds of 6/1 in a field of fourteen runners for the Derby on 3 June.
Confusingly, there were two horses in the race called “Ibrahim”, one of whom, a colt owned by Lord Jersey, started 7/4 favourite.
Heavy rain had made the ground soft and muddy, but did not deter the usual huge crowds who were entertained between races by “conjurors, learned donkies, posture masters, Punchinellos &c”.
Several false starts saw the race beginning half an hour late, at a few minutes after three o’clock.
Although the early pace was fast, almost all the leading contenders were still in contention as the field turned into the straight, and spread out across the width of the course.
The closing stages saw four horses enter the final furlong almost level: Ascot and Lord Jersey's Ibrahim raced along the inside rail, while Mundig and the 100/1 outsider Pelops ran up the stands side.
In an extremely close finish, Mundig was declared the winner by a neck from Ascot.
The race was described as “one of the closest and best contested Derbys ever run”.
In addition to the winners prize of £3,550, Bowes and his associates were reported to have taken up to £20,000 in winning bets.
Much credit for the win was given to Bill Scott, who rode a very strong finish, making extensive use of his whip and spurs.
He had backed the colt heavily and was reported to have said on the eve of the race that he would win the Derby even if he had to “cut Mundig to pieces”.
 According to the Court Journal, Mundig's win was greeted with great celebrations by his Northern supporters who waved impromptu flags and left the course crying “Yorkshire for ever!
Mundig for ever!”
Mail coaches passing through Yorkshire blew horns and flew flags in John Bowes black racing colour to mark Mundig's victory, leading one vicar to believe that the King must have died.

Following his very hard race at Epsom, Mundig did not appear again until 15 September when he ran in the Great St Leger at Doncaster before a large and fashionable crowd which included Princess Victoria.
He was not considered a serious contender on the day of the race, with his stable companion Hornsea being regarded as Scott's main hope.
He was towards the rear of the field throughout the race and  finished ninth of the eleven runners behind Queen of Trumps.
On the following day he started  4/6 favourite for the Foal Stakes over one and a half miles and won easily by three lengths, having led from the start against weak opposition.
Mundig was unraced as a two-year-old, but his performances in home exercise gallops and private trial races made him a fancy for the Derby. He was the subject of heavy betting by the Scott family and by  Bowes, although a great deal of secrecy surrounded his form, making him a very "dark horse".  In April, Scott discovered that one of his stable lads had been passing information to bookmakers. Rather than expose and dismiss the lad, Scott fed him false information, to the effect that the colt would not run at Epsom. Mundig's odds lengthened and his connections were able to back him at 50/1.
Ridden by Bill Scott, the brother of his trainer, Mundig started at odds of 6/1 in a field of fourteen runners for the Derby on 3 June. Confusingly, there were two horses in the race called “Ibrahim”, one of whom, a colt owned by Lord Jersey, started 7/4 favourite. Heavy rain had made the ground soft and muddy, but did not deter the usual huge crowds who were entertained between races by “conjurors, learned donkies, posture masters, Punchinellos &c”. Several false starts saw the race beginning half an hour late, at a few minutes after three o’clock. Although the early pace was fast, almost all the leading contenders were still in contention as the field turned into the straight, and spread out across the width of the course. The closing stages saw four horses enter the final furlong almost level: Ascot and Lord Jersey's Ibrahim raced along the inside rail, while Mundig and the 100/1 outsider Pelops ran up the stands side. In an extremely close finish, Mundig was declared the winner by a neck from Ascot. The race was described as “one of the closest and best contested Derbys ever run”. In addition to the winners prize of £3,550, Bowes and his associates were reported to have taken up to £20,000 in winning bets. Much credit for the win was given to Bill Scott, who rode a very strong finish, making extensive use of his whip and spurs. He had backed the colt heavily and was reported to have said on the eve of the race that he would win the Derby even if he had to “cut Mundig to pieces”.  According to the Court Journal, Mundig's win was greeted with great celebrations by his Northern supporters who waved impromptu flags and left the course crying “Yorkshire for ever! Mundig for ever!” Mail coaches passing through Yorkshire blew horns and flew flags in John Bowes black racing colour to mark Mundig's victory, leading one vicar to believe that the King must have died.
Following his very hard race at Epsom, Mundig did not appear again until 15 September when he ran in the Great St Leger at Doncaster before a large and fashionable crowd which included Princess Victoria. He was not considered a serious contender on the day of the race, with his stable companion Hornsea being regarded as Scott's main hope. He was towards the rear of the field throughout the race and  finished ninth of the eleven runners behind Queen of Trumps. On the following day he started  4/6 favourite for the Foal Stakes over one and a half miles and won easily by three lengths, having led from the start against weak opposition.
Mundig