In 1913, Rothko's family emigrated from Russia to the U.S. and settled in Portland, Ore. During his youth, he was deeply involved in politics and social issues. He entered Yale University in 1921 with the intention of becoming a labour leader but dropped out after two years and wandered across the U.S. In 1925, he settled in New York City and began to pursue painting. Although he briefly studied under the painter Max Weber, he was largely self-taught.
Rothko initially worked in a realistic style, which reached its peak with his Subway series in the late 1930s, depicting the loneliness of people in drab urban environments. This style gave way in the early 1940s to the semi-abstract biomorphic forms seen in the ritualistic Baptismal Scene (1945). By 1948, however, he had developed a highly personal form of Abstract Expressionism. Unlike many of his contemporaries, Rothko did not rely on dramatic techniques such as violent brushstrokes or the dripping and splattering of paint. Instead, his virtually gestureless paintings achieved their impact through the juxtaposition of large areas of melting colours that seemed to float parallel to the picture plane in an indeterminate, atmospheric space.
Rothko spent the remainder of his life refining this basic style through continuous simplification. He limited his designs to two or three "soft-edged" rectangles that nearly filled the wall-sized vertical formats, resembling monumental abstract icons. Despite their large size, his paintings exuded a remarkable sense of intimacy through the play of nuances within the local colour.
From 1958 to 1966, Rothko worked intermittently on a series of 14 immense canvases, the largest of which was approximately 11 × 15 feet (3 × 5 metres). These paintings were eventually placed in a nondenominational chapel in Houston, Texas, which was named the Rothko Chapel after his death. These works were virtual monochromes of darkly glowing browns, maroons, reds, and blacks, their sombre intensity revealing the deep mysticism of Rothko's later years. Plagued by ill health and the belief that he had been forgotten by those artists who had learned the most from his painting, he took his own life.
After his death, the execution of Rothko's will led to one of the most spectacular and complex court cases in the history of modern art, lasting for 11 years (1972–82). The misanthropic Rothko had hoarded 798 paintings, as well as many sketches and drawings. His daughter, Kate Rothko, accused the executors of the estate (Bernard J. Reis, Theodoros Stamos, and Morton Levine) and Frank Lloyd, the owner of Marlborough Galleries in New York City, of conspiracy and conflict of interest in selling the works, effectively enriching themselves. The courts ruled against the executors and Lloyd, who were heavily fined. Lloyd was tried separately and convicted on criminal charges of tampering with evidence. In 1979, a new board of the Mark Rothko Foundation was established, and all the works in the estate were divided between the artist's two children and the Foundation. In 1984, the Foundation's share of works was distributed to 19 museums in the United States, Great Britain, the Netherlands, Denmark, and Israel, with the best and largest proportion going to the National Gallery of Art in Washington, D.C.
Source: https://www.britannica.com/biography/Mark-Rothko