Susanna (later Sonja) Graf was born and grew up in Munich, Germany, to Russian and Belarussian parents. From an early age she spent as much time as possible in the chess cafes of the city, which Graf would later recount served as a refuge from her abusive father. There she became a protege of Siegbert Tarrasch. By the middle 1930s she was regarded as one of the strongest female players in the world. However, her Russian background and somewhat unconventional lifestyle made her unpopular with the Nazi authorities, and in 1934 she left Germany to adopt the lifestyle of an itinerant chess professional. During the next five years she would live at different times in England, Spain, Austria, Sweden, the Netherlands, and Poland, as well as Germany.
Graf lost to Vera Menchik in matches in 1934 (+1 -3 =0) and 1937 (+2 -9 =5); the first of these was generally regarded as an exhibition match, while the second was reportedly a women's world championship title match. She also lost a match to the problemist Heuaeker (+0, =0, -6).
Vera Menchik was absent from the Semmering 1936 women's tournament and Graf took 1st place. Graf also played in the Women's World Championship tournament in 1937 and 1939, tying for third in 1937 and finishing second to Menchik in 1939. She would be awarded the WIM title in 1950.
Barred from representing Germany in international competition, she was nevertheless invited to play for the women's world championship in Argentina in 1939 by FIDE; during the competition she played under a flag bearing the Spanish word "libre" ("free"). World War II broke out during the tournament, and Graf remained in Argentina after the tournament's conclusion. During her time in that country, she published two books in Spanish, "Asi Juega una Mujer" ("This is How a Woman Plays", about her chess career), and "Yo Soy Susann" ("I am Susan", about her abusive childhood).
When former world champion Max Euwe visited Argentina in 1947, he (perhaps unintentionally) introduced Graf to a visiting American sailor and ardent chess fan, Vernon Stevenson. Later that year she married Stevenson, moved to Hollywood, California, and began playing under the name Sonja Graf-Stevenson. During her early years in the United States Graf-Stevenson played relatively little, giving birth to a son in 1951. However, she eventually resumed active play, winning the California Women's Championship in 1954 (scoring 8-0) and 1956, sharing the US Women's title with Gisela Kahn Gresser in 1958-59 and winning that title outright in 1964. By 1964 she had moved to New York and was giving lessons in the Greenwich Village chess studio run by Lisa Lane.
She passed away in New York in 1965.
Wikipedia article: Sonja Graf