The director's function is to ensure the quality and completeness of theatre production and to lead the members of the creative team into realizing their artistic vision for it.
In contemporary theatre, after the playwright, the director is generally the principle visionary, making decisions on the artistic conception and interpretation of the play and its staging.
Actors were generally semi-professionals, and the director oversaw the mounting of plays from the writing process all the way through to their performance, often acting in them too, as Aeschylus for example did.
[3] In medieval times, the complexity of vernacular religious drama, with its large scale mystery plays that often included crowd scenes, processions and elaborate effects, gave the role of director (or stage manager or pageant master) considerable importance.
Holding a prompt book, the central figure directs, with the aid of a long stick, the proceedings of the staging of a dramatization of the Martyrdom of Saint Apollonia.
The modern theatre director can be said to have originated in the staging of elaborate spectacles of the Meininger Company under George II, Duke of Saxe-Meiningen.
Simultaneously, Constantin Stanislavski, principally an actor-manager, would set up the Moscow Art Theatre in Russia and similarly emancipate the role of the director as artistic visionary.
Post World War II, the actor-manager slowly started to disappear, and directing become a fully fledged artistic activity within the theatre profession.
Great forces in the emancipation of theatre directing as a profession were notable 20th-century theatre directors like Vladimir Nemirovich-Danchenko, Vsevolod Meyerhold, Yevgeny Vakhtangov, Michael Chekhov, Yuri Lyubimov (Russia), Orson Welles, Peter Brook, Peter Hall (Britain), Bertolt Brecht (Germany), Giorgio Strehler, and Franco Zeffirelli (Italy).
and ex-producer of two LORT companies) led for many years a graduate programme based on the premise that directors are autodidacts who need as many opportunities to direct as possible.