[1] He was apprenticed to Frank Neal in Newmarket but his first flush of success came riding for his brother-in-law, Richard Boyce, whose major owners were Messrs Ladbroke and Shakespeare.
By this time in his career, his principal patrons were Lord George Cavendish and the Marquess of Exeter It is said of Arnull that "lack of tactical skill prevented him from being a great jockey."
[2] Nevertheless, he was a "fearless rider, whose strength made him formidable in a finish, and absolutely honest.
This led Newmarket locals to encourage tramps to target him with their begging.
[2] He suffered from gout from an early age and it finally killed him on 29 April 1835, just after he had started training for Lord Lichfield.