By the late 1970s, boxing had lapsed into a moribund state and interest in it was on the wane. In 1980, however, the sport was resuscitated by a riveting series of bouts involving an improbably dissimilar quartet: Sugar Ray Leonard, Marvellous Marvin Hagler, Thomas Hearns and Roberto Duran. Like Ali and Frazier, Dempsey and Tunney, Robinson and LaMotta, the 'Four Kings of the Ring' brought out the best in each other, producing unprecedented multi-million-dollar gates along the way. Each of the nine bouts between the four men was memorable in its own way and at least two of them - Leonard-Hearns in 1981 and Hagler-Hearns in 1985 - are commonly included on any list of the greatest fights of all time. The controversial outcome of another - the 1987 Leonard-Hagler fight - remains the subject of heated debates amongst fans to this day. In Four Kings, award-winning journalist George Kimball documents the remarkable effect they had on the sport and argues that we will never see their likes again. Leonard, Hagler, Hearns and Duran didn't set out to save boxing from itself in the post-Ali era, but somehow they managed to do so.