Viktor Korchnoi was a prominent Soviet-born chess player, born on March 23, 1931, in Leningrad, Russia. He became one of the world's top chess players during the mid-20th century and was known for his aggressive playing style and deep strategic understanding. Korchnoi competed in multiple World Chess Championships, notably challenging Anatoly Karpov in the 1974 and 1978 matches. In 1976, Korchnoi defected to the West, settling in Switzerland. His defection marked a significant moment in chess history, as it highlighted the political tensions of the Cold War era. Korchnoi continued to play competitively into his later years, earning respect for his contributions to the game until his passing on June 6, 2021.