The third person with whom the archon concerned himself was the “protagonist” (the chief actor)—after the middle of the fifth century; before then it appears that poets chose their protagonists. In the middle of the fifth century a protagonist was selected by the archon and one assigned to each tragic poet by lot. (The chief actor provided his subordinates himself.) This change came at about the time when three actors were regularly employed in each tragedy and when the contests in acting were instituted; a prize for acting was awarded, and the successful actor had the right to perform the following year. As the importance of the actor increased—Aristotle tells us that in his time the success of a play depended more upon the actor than upon the poet[172]—it was considered unfair that one poet should have the best performer for all his plays. In the middle of the fourth century the arrangement was introduced that each protagonist should play in one tragedy only of each poet. Each dramatist competed with a tetralogy[173] (that is, “four works”) consisting of three tragedies and a satyric play, and the claims of these three tetralogies were decided by five[174] judges. Some days before the competition began, the Council of the State and the choregi selected a number of names from each of the ten tribes. These names were sealed up in urns, which were produced at the opening of the festival. The archon drew one name from each urn, and the ten citizens so selected were sworn as judges and given special seats. After the conclusion of the performances each of the ten gave his verdict on a tablet, and five of these were drawn by the archon at random; these five judgments gave the award. In this method the principle of democratic equality and the necessity to rely on expert opinion were well combined. When the votes had been collected, a herald proclaimed the name of the successful poet and of his choregus, who were crowned with ivy (a plant always associated with Dionysus). There is no evidence that a dramatic choregus was given any further reward: the prize of a tripod was only for dithyramb. The poet received, tradition said, a goat[175] in early times; after the State-supervision began, a sum of money from public funds was paid to each of the competitors. Records of the results were inscribed upon tablets and set up both by the victorious choregi and by the State. It is from these, directly or indirectly, that our knowledge of the facts is obtained; directly, because such inscriptions have been discovered in Athens, indirectly, because they were the basis of written works on the subject. Aristotle wrote a book called _Didascaliæ_ (διδασκαλίαι), that is, “Dramatic Productions”; though it is lost, later works were based upon it, and it is from these that the Greek “Arguments” to the existing plays are derived. IV. THE MOUNTING OF A TRAGEDY