Sophocles mission was to improve the tragic art, in a time, when Greek drama was in decline and in deep need for a change.
The first plays included only a chorus, but earlier playwrights had added one, and then two actors. Everything was a dialogue between the chorus - collective character, and the two actors. One of Sophocles' earliest innovations was the addition of a third actor. Afterwards he reduced the role of the chorus and strengthened the individuality of his characters.
Their interior life became a priority and they started to have powerful interaction with the other characters. Social, psychological and philosophical dimensions were added to the play. All of this contributed to the development of the dialogue.
Another of his interests was the arrangement of the stage. He carefully supervised the way the setting was painted and how the stage was arranged. Everything was supposed to give a more powerful visual impact. Sophocles’ great reputation determined many foreign rulers to invite him to their courts, but Sophocles never accepted any invitations.