In tragedy the changes were similar, though less distinct. The protest against the lawlessness of the early drama was manifested in the infrequency of chronicle plays and the appearance of tragedies presenting foreign, and especially Roman, history with due regard for both historical truth and tragic structure. Realism appeared just at the beginning of the century in a number of domestic tragedies that violated the established conventions by dealing with actual events, contemporary society, and humble persons. Satire of contemporary manners became frequent in tragedy, and satirical comedies often dealt with tragic events and exercised an influence on pure tragedy similar to that exercised by romantic comedy in the earlier period. Up to this time popular tragedy had hardly received critical consideration even from the dramatists themselves. Marlowe, Kyd, Shakespeare, and others had been mainly concerned in telling stories on the stage without much consciousness of theory or of the types of drama which they were creating. In this period, however, the demarcation between tragedy and comedy and the definition of a conception of tragedy became positive both in occasional critical comment and in the practice of the dramatists. The old types, however, survived. Medleys of various kinds of tragedy and comedy, such as "Old Fortunatus" or "The Downfall and Death of Robert, Earl of Huntingdon," are not found much after the beginning of the century; but the revenge tragedy received a remarkable development by Marston, Chettle, Tourneur, Chapman, and Jonson, to say nothing of Shakespeare. Practically synchronous with the period of Shakespeare's great tragedies are these several interesting developments: the domestic tragedies, and especially the allied work of Heywood; the Roman historical tragedies, especially the two by Jonson; the French historical tragedies by Chapman; and the various revenge plays, beginning with Marston's "Antonio and Mellida." These dramatists, however, were mainly occupied with comedy, and no one of them devoted himself as exclusively to tragedy as did Shakespeare. Nor did any of them equal him in immediate popularity. The imitative methods of his artistic apprenticeship had given place to a maturity and independence of art that at once won a supremacy in tragedy even greater than that already attained in comedy. Yet in themes and treatment there is no divorce from the practice of his fellow dramatists. His genius continued responsive to the demands of the stage of the day, and it felt the changes in dramatic conditions, of which we have been noticing some symptoms, and which made the tragedies of others as well as his own more satirical and realistic than those of Marlowe's time, more concerned with the problem of evil, more conscious and critical in their art, and in their style less lyrical and descriptive, more reflective and sententious.