World Chess Championship Topalov, and negotiations began for a Kramnik–Topalov match to unify the title. The FIDE World Chess Championship 2006 reunification match between Topalov and Kramnik was held in late 2006. After much controversy, it was won by Kramnik. Kramnik thus became the first unified and undisputed World Chess Champion since Kasparov split from FIDE to form the PCA in 1993. Kramnik played to defend his title at the World Chess Championship 2007 in Mexico. This was an 8-player double round robin tournament, the same format as was used for the FIDE World Chess Championship 2005. This tournament was won by Viswanathan
FIDE World Chess Championship 2005 be required to compete; but that as part of the "Prague Agreement", his defense of his title in the Classical World Chess Championship 2004 entitled him to direct entry to a match against the FIDE World Champion for the unified world title. After the tournament, he expressed his willingness to play such a match against Topalov. Although Topalov initially declined Kramnik's offer, he later acceded. The two contested the FIDE World Chess Championship 2006 to reunify the title, with Kramnik emerging the winner. FIDE World Chess Championship 2005 The FIDE World Chess Championship 2005 took place in Potrero de los