The World Chess Championship is played to determine the world champion in chess. The current world champion is Ding Liren, who defeated his opponent Ian Nepomniachtchi in the 2023 World Chess Championship. Magnus Carlsen, the previous world champion, declined to defend his title.
The first event recognized as a world championship was the 1886 match between the two leading players in the world, Wilhelm Steinitz and Johannes Zukertort. Steinitz won, becoming the first world champion. From 1886 to 1946, the champion set the terms, requiring any challenger to raise a sizable stake and defeat the champion in a match in order to become the new world champion. Following the death of reigning world champion Alexander Alekhine in 1946, FIDE (the International Chess Federation) took over administration of the World Championship, beginning with the 1948 World Championship tournament. From 1948 to 1993, FIDE organized a set of tournaments to choose a new challenger every three years. In 1993, reigning champion Garry Kasparov broke away from FIDE, which led to a rival claimant to the title of World Champion for the next thirteen years. The titles were unified at the World Chess Championship 2006, and all subsequent matches have once again been administered by FIDE.
Since 2014, the championship has settled on a two-year cycle, although the 2020 and 2022 matches were postponed to 2021 and 2023 respectively because of the COVID-19 pandemic.
Though the world championship is open to all human players, there are separate championships for women, under-20s and lower age groups, and seniors; as well as one for computers. There are also chess world championships in rapid, blitz, correspondence, problem solving, and Fischer random chess.
Before Steinitz and Zukertort, no chess player seriously claimed to be champion of the world, although the phrase was used by some chess writers to describe other players of their day. A series of players regarded as the strongest (or at least the most famous) in the world extends back hundreds of years.