Once regarded as something that happens exclusively in Guy Ritchie films and on gypsy sites, bare knuckle boxing is fast becoming a thriving scene in the UK – the ultimate British bloodsport.When Clive Martin embeds with the bare knuckle boxing elite, what he discovers is not dissimilar to Fight Club; IT technicians, builders, lifestyle coaches and even a solicitor, all throwing their unprotected fists into each other's faces. It's a subculture of honour, pride and violence.As the UK prepares to play host to the first US vs UK bare knuckle title fight in 150 years – the biggest event the scene has known since it went underground in the 19th Century – Clive tries to find out if violence is a cause or effect for these angry young men.