Between 1921 and 1933, while painter Otto Dix was in his 30s and early 40s--in the years following the Great War, in which he had fought for Germany at the Somme, and which had driven him to make some of the most controversial, violent art of his generation--Dix put much of his artistic energy into portraits of his lover and later wife, Martha. The paintings, watercolors, drawings and humorous sketches brought together here show Martha Dix advancing through roles as a sophisticated, emancipated woman; as lover, muse, and intellectual companion; and then as mother and heart of the family. The painterA­s widely varying attitudes toward his most frequent model, which range from admiration and intimacy to increasing distance, transpose themselves into a myriad of styles. The titles of the works, which range from emotionally charged imagery to matter-of-fact description, underscore this shift. Martha DixA­s portraits, organized here by the Otto Dix Foundation she helped to found, document...