Chulmleigh was a "massive" bay horse standing 16.3 hands high[3] bred in England by William Tatem, 1st Baron Glanely who also owned him during his racing career.
The horse had an unusual facial marking in the form of an abbreviated white blaze which began half-way down his face and ran down to his nose.
Chulmleigh did not compete as a three-year-old until July and then made no impact in a seven furlong maiden race at Newmarket Racecourse as he finished unplaced at odds of 20/1.
[3] At York Racecourse in August, Chulmleigh showed high-class form for the first time as he produced a strong late run and finished a close second to the gelding Mange Tout in the Great Yorkshire Stakes.
[9] Ridden by Gordon Richards, who only took the ride when his intended mount was withdrawn,[10] he started an 18/1 outsider in a fifteen-runner field headed by the Epsom Derby winner Mid-day Sun.
Chulmleigh, however, produced a strong late run to overtake Fair Copy inside the last 50 yards and won by half a length in what was described as a "sensational finish".