Akiba Kiwelowicz Rubinstein (1 December 1880 – 14 March 1961) was a Polish chess player. He is considered to have been one of the greatest players never to have become World Chess Champion. Rubinstein was granted the title International Grandmaster in 1950, at its inauguration. In his youth, he defeated top players José Raúl Capablanca and Carl Schlechter and was scheduled to play a match with Emanuel Lasker for the World Chess Championship in 1914, but it was cancelled due to the outbreak of World War I. He was unable to re-create consistently the same form after the war, and his later life was plagued by mental illness. Source: Wikipedia (en)