Garry Kimovich Kasparov (13 April 1963) is a Russian (formerly Soviet) chess Grandmaster, former World Chess Champion, writer, and political activist, considered by many to be the greatest chess player of all time. From 1986 until his retirement in 2005, Kasparov was ranked world No. 1 for 225 out of 228 months. His peak rating of 2851, achieved in 1999, was the highest recorded until being passed by Magnus Carlsen in 2013. Kasparov also holds records for consecutive professional tournament victories (15) and Chess Oscars (11).
Source: Wikipedia
