King was born on Silver Street, Stepney, East London and at an early age joined the Royal Navy, journeying several times to the coast of Africa.

Retiring from the navy while still a young man, he became a docker, rising to the position of foreman, where his skills with his fists earned him respect and some limited notoriety, following several brawls with colleagues.

[3] King's brawling bought him to the attention of the retired boxing champion Jem Ward who began to train him in earnest.

[7] His first title bout, staged in Godstone, England, was fought bare knuckle under London Prize Ring Rules and lasted for 43 rounds and 68 minutes.

[8][3][9] Mace and King met on the banks of the River Medway, twenty-eight miles from London for a rematch less than a year later on 26 November 1862 for £200 a side.

[11][12][13] King's next fight was a defence of the English heavyweight championship and took place on a sunny morning at 10 am on 10 December 1863[14] for the exceptional sum of £1000 a side against John C Heenan.

Heenan had been unofficially acclaimed the heavyweight champion, so King and his seconds knew the importance of taking the bout to defend the title.

[15] The bout was held at Cockmounts Farm, Wadhurst, East Sussex and was fought with bare-knuckles using London Prize Ring Rules.

Called "fibbing" at the time, holding an opponent by the neck and striking him was a move usually allowed under London Prize Ring Rules.

Mace was frustrated and angry at not being given the opportunity to regain his heavyweight title, and in order to prompt a match deliberately set out to pick a fight with King in the street.

He met his first defeat in February 1865, against the rower Caffin after a foul was called by the referee and the race was run a second time.

Unlike many of his contemporaries who relied on the charity and munificence of their former patrons and fans for support, King prospered as a bookmaker, primarily at horse tracks, often as an agent for Lord Hastings.

It is believed he once made £4000 as a commission agent betting on the horse Melton at the Liverpool Autumn Cup in 1886, retiring from bookmaking not long after.