Mark Rothko, a titan among modern painters, said that the subject matter of his paintings was the extremes of human emotion. His extraordinary achievement was the communication of tragedy and elation through forms reduced to starkest simplicity-oftentimes a pair of rectangles.Born Marcus Rothkowitz in Dvinsk, Russia (now Daugavpils, Latvia), the artist emigrated to the United States at the age of 10. After a series of artistic metamorphoses, he established himself as a leader among New York's