Sigrid Undset (20 May 1882 – 10 June 1949) was a Norwegian novelist who was awarded the Nobel Prize for Literature in 1928.Undset was born in Kalundborg, Denmark, but her family moved to Norway when she was two years old. In 1924, she converted to Catholicism. She fled Norway for the United States in 1940 because of her opposition to Nazi Germany and the German invasion and occupation of Norway, but returned after World War II ended in 1945.
Her best-known work is Kristin Lavransdatter, a trilogy about life in Norway in the Middle Ages, portrayed through the experiences of a woman from birth until death. Its three volumes were published between 1920 and 1922.