Few theatrical epochs have had the lasting international impact of Russian modernist theater. The two most influential theater directors to emerge from this era, Konstantin Stanislavsky and Vsevolod Meyerhold, continue to provide rich fodder in their acting theories and performance practices for contemporary theater creators worldwide. Meanwhile, the early 20th century in Russian theater was a time of fierce theoretical and practice-based polemics, rapid technological development, and monumental shifts in theatrical practice as actors were trained in specific internal and external (bodily) techniques and directors took on increasingly more importance for the creative design of a production. At the same time, popular theater was a major avenue of theatrical development in the era, with cabaret and other minor forms enjoying great popularity in Russia and on tours abroad, while avant-garde artists like the Russian futurists created shocking street-based performance art that capitalized on the modernist sense of newness and rejection of the past. Points of debate in studies of Russian modernist theater include disagreement over the definition of what counts as modernist and how seriously to take the polarization and polemics that these theater artists themselves espoused. While modernist theater in Europe is known for its emphasis on closet drama, on grand experiments that were ultimately unperformable, and on mistrust of language and representation, performance practice took a related but different path in Russian culture in the first decades of the 20th century. Despite a great diversity of performance styles, venues, and audiences, theater in the age of Russian modernism unifies around a few key points. First, it placed great emphasis on honing and highlighting the various physical and mental skills of the actor. Second, Russian modernist theater generally valued language and the literary tradition, both Russian and global, despite some efforts to break with literature in theater. Third, theater of this era presented a tone of irony, self-consciousness, and theatricalism. In all its manifestations, it was experimental and self-reflexive, interrogating theater’s relationship to the world and boldly devising new forms. Fourth, Russian modernist theater was richly integrated into its artistic, intellectual, and political context, with ties to science, philosophy, psychology, visual arts, music, dance, film, and literature. Theater came to serve the political ends of the young Soviet nation in the 1920s, though politics were not a predominant force in theater throughout Russian modernism. Theater was not immediately strongly affected by the Russian Revolution of 1917, but by the end of the 1920s, theater was forced to bend to the strong will of Soviet censors, and by the mid-1930s, theatrical innovation was greatly diminished under Stalin-era censorship and its insistence on the style of socialist realism, as well as the general threat of the Stalinist Terror.