Russian and later Soviet cinema was a hotbed of invention, resulting in world-renowned films such as ''The Battleship Potemkin''. Soviet-era filmmakers, most notably Sergei Eisenstein and Andrei Tarkovsky, would go on to become among of the world's most innovative and influential directors. Eisenstein was a student of Lev Kuleshov, who developed the groundbreaking Soviet montage theory of film editing at the world's first film school, the All-Union Institute of Cinematography. Dziga Vertov's "Kino-Eye" theory had a huge impact on the development of documentary filmmaking and cinema realism. Many Soviet socialist realism films were artistically successful, including ''Chapaev'', ''The Cranes Are Flying'', and ''Ballad of a Soldier''.