Born December 24, 1868 in Berlinchen in the Neumark, Germany. Died January 1941.
The second ever World Chess Champion, and the person who held the title of World Champion longest (28 years) in the years 1894-1921. He won the title from Wilhelm Steinitz, and eventually lost it to Jose Raul Capablanca.
Lasker is widely regarded as the father of psychological chess. He saw the game of chess as a fight between individuals, and he often triumphed in positions that other masters would have deemed weak or losing positions, on the merit of his incredible fighting spirit.
He was also a supreme theorist. His spiritual father was the very man he defeated for the title, Wilhelm Steinitz. In his investigations of the game, Lasker elaborated upon and refined the theories that were pioneered by Steinitz, and added to these theories his own superior notion of the psychology of the fight, to make himself the most formidable player of his day.
His main ideological opponent was Siegbert Tarrasch, who was a very tough fighter in his own right, but who was more dogmatic in his application of Steinitz' ideas, more enamored of technique, and more of a stubborn materialist than Lasker. These qualities later put Tarrasch at odds with Aron Nimzovich, who was one of the most revolutionary chess theorists of the time, and a strong tournament player, but who lacked the fighting spirit and psychological fortitude neccessary to rise to challenge either Lasker's or Capablanca's title.
As champion, Lasker reigned throughout the transition from classical to hypermodern chess. His play in the openings was often mysterious to the other masters of the day, and seemed to be theoretically unsound. The same could be said for the entire school of hypermodernism that was arising at that time. Both Lasker and the Hypermoderns were disciples of the the Steinitz principals, and their understanding of the implications of these principals, particularly as they pertained to the center, went beyond the limited scope of dogmatic masters like Tarrasch.
Yet the concensus seems to be that Lasker was primarily a master of psychology, who rose from weak positions to triumph by throwing his opponents off their game. From an unattributed article, published after the New York Tournament of 1924 and quoted in Richard Reti's Masters of the Chessboard:
"For him the essential element is this contest
of nerves; he uses the medium of the chess game
to fight above all his opponent's psyche, and he
knows how to bring about the nervous collapse,
which, otherwise, occurs only after a mistake,
even before a mistake has been made and to make
this the very cause for subsequent errors...
All of a sudden Lasker begins to play magnificently
and to show his real strength. The opponent's
nervous collapse and shattered morale finally
results in a catastrophe at the chessboard."