For all questions related to the World Chess Championship: its holders, contestants, history, etc.
In 1886 Wilhelm Steinitz won the first match billed as a world championship, defeating Johannes Zukertort in a twenty-game match (+10 =5 -5). The crown then passed directly from champion to champion via match play until 1948, when Alexander Alekhine died as champion. At that point, FIDE held a match-tournament to determine a new world champion, which was won by Mikhail Botvinnik. The crown remained solely under the auspices of FIDE until 1993, when sitting champion Garry Kasparov broke away from FIDE to form his own rival organization, the PCA. This ushered in an era of two split titles, which lasted until 2006, when Vladimir Kramnik (holder of the crown coming from Kasparov's branch) defeated Veselin Topalov (holder of the FIDE crown) in a reunification match. Since then, the crown has remained again under the auspices of FIDE.