At the end of the nineteenth century European pimps and ‘white slavers’ established a hugely successful global market for commercial sex. Criminal syndicates from Buenos Aires to London and from Cape Town to New York were able to organise the seduction or rape of women in under-developed parts of Europe and their ‘export’ as prostitutes to meet an insatiable demand for sexual services. For three turbulent decades before the First World War, Joseph Silver – brothel-owner, pimp and trafficker in women on four continents – was central to this hidden world of betrayal, intrigue, lust and sexual slavery. Burglar, gun-runner, jewel-thief, rapist, safe-cracker and sodomist, Silver’s notoriety was captured in the most confidential correspondence of a dozen countries in the western world. What those in charge of law-enforcement agencies kept to themselves, however, was how their officers had attempted to use Silver as an informer to infiltrate syndicates built on ‘vice’, only to have him outwit them as he moved in the dangerous space between police and prostitutes. A disturbed adolescent, youthful predator and adult misogynist driven by dark biblical and medieval obsessions, Silver’s mental universe remained largely hidden from his family, other gangsters and police handlers. In this first reconstruction of the life of a dangerous psychopath, Charles van Onselen situates the private life of one man amidst the demi-monde of the Atlantic world to identify the most infamous serial killer of all time – for Joseph Silver’s darkest secret of all lay in London, in Whitechapel, in the autumn of 1888.