A theatre director or stage director is a director/instructor in the theatre field who oversees and orchestrates the mounting of a theatre production (a play, an opera, a musical, or a devised piece of work) by unifying various endeavours and aspects of production. 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. The director therefore collaborates with a team of creative individuals and other staff, coordinating research, stagecraft, costume design, props, lighting design, acting, set design, stage combat, and sound design for the production. If the production he or she is mounting is a new piece of writing or a (new) translation of a play, the director may also work with the playwright or translator. In contemporary theatre, after the playwright, the director is generally the primary visionary, making decisions on the artistic concept and interpretation of the play and its staging. Different directors occupy different places of authority and responsibility, depending on the structure and philosophy of individual theatre companies. Directors use a wide variety of techniques, philosophies, and levels of collaboration.
In ancient Greece, the birthplace of European drama, the writer bore principal responsibility for the staging of his plays. 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. The author-director would also train the chorus, sometimes compose the music, and supervise every aspect of production. The fact that the director was called didaskalos, the Greek word for "teacher," indicates that the work of these early directors combined instructing their performers with staging their work.
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. A miniature by Jean Fouquet from 1460 (pictured) bears one of the earliest depictions of a director at work. 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. According to Fouquet, the director's tasks included overseeing the erecting of a stage and scenery (there were no permanent, purpose-built theatre structures at this time, and performances of vernacular drama mostly took place in the open air), casting and directing the actors (which included fining them for those that infringed rules), and addressing the audience at the beginning of each performance and after each intermission.