Ernst Ludwig Kirchner’s “Portrait of Otto Müller”—with its vibrant, modulated color and penetrating psychological force—is emblematic of the artist’s innovative approach to technique and imagery. A pivotal figure of the German Expressionist movement, Kirchner first met Müller, also a painter-printmaker, in 1910. Müller then joined “Die Brücke” (The Bridge), the group Kirchner had helped found in 1905, which was instrumental in promoting Expressionism. The period between 1915 and 1919 marked Kirchner’s most concentrated and productive phase of work with portrait prints, which he made primarily as large-format woodcuts.