Nikolai Sergeyevich Valuev is a Russian politician and former professional boxer. He competed in boxing from 1993 to 2009, and held the World Boxing Association (WBA) heavyweight title twice between 2005 and 2009. At a height of 2.13 metres and a peak weight of 151 kilograms, Valuev is best known for being the tallest and heaviest world champion in boxing history. He is also the first heavyweight champion to have finished his career without ever being knocked down, and he is the fifth to have never been stopped.