This is a comprehensive biography of Clarence Charles Hatry, 1888-1965, an enigmatic and charismatic public figure. Hatry was the son of Jewish immigrant parents who became a company promoter and whose companies collapsed in 1929, leading to a crash on the London stock exchange. He was brought down by a desperate fraud. At his trial three months later, the judge said that he could not imagine a worse crime. Analysing transactions in detail, the book reveals Hatry’s brilliance as a manipulator and a world-class networker and persuader. It also demonstrates his vain belief in his ability to overcome any risks and his insecurity which led him to surround himself with sycophants who would not challenge his ideas. It shows how others used Hatry to make money, and, as he destroyed himself, as a scapegoat who distracted from the City’s failings. Despite his deepest ambitions, he remained an outsider. Until now there has been no full biography of Clarence Hatry, which may be attributable to the lack of records, as his business papers are believed all to have been destroyed. This comprehensive biography is based on examination of the memoirs of Hatry’s contemporaries, the archives and records which they and their companies preserved, and press reports of Hatry’s activities. Marking the 90th anniversary of Hatry’s collapse, this book will be important reading for academics and researchers looking to gain a greater understanding of the context of the 1929 crash, or of financial crises generally.