 Johnson probably began fighting in June 1783, at the age of thirty-three, although Brailsford suggests it was 1781 or slightly earlier.Johnson had unintentionally slighted a carman (horse-drawn wagon driver) and fighter called Jack Jarvis, who then called for Johnson to fight him as a matter of honour.Johnson comprehensively battered the experienced Jarvis at Lock's Fields, and his name came to the attention of professional fighters.