Centuries later, in the Roman era, the theatre came to be inclosed within boundary walls, but still without a roof. It had changed its form, and was now built more ornately and upon level ground. The exhibitions had become more secular, the altar had been removed, and all performances, whether choral, musical or dramatic, were transferred from the orchestra to the stage. The orchestra, considerably reduced in size, was given up to seats for the spectators. The first recorded stone theatre in Rome was built by Pom-pey in 55 B. C. It consisted of three floors separated by ample corridors, and each corridor was approached by broad staircases that enabled patrons to reach their respective places. Although the Roman theatre was quite open at the top, a canvas sheet was later stretched across the auditorium, worked by means of pulley cords, to protect the auditors from the heat of the sun.
In the first century of the Christian era the Roman theatre developed mime plays, a species of true pantomime that was secular in its character. These unspoken plays and the gladiatorial games of that day were rivals for the public favor, and the Church was not slow in denouncing this so-called prostitution of the religious stage. From that time began the decadence of the ancient theatre, and it lay dormant until its revival in the mediaeval period, centuries later.
Just as the ancient theatre, originally designed for joyous display through the religious enthusiasm of a devout people, and later assuming a more secular aspect that necessitated corresponding changes in architecture, so, too, has the theatre of a later civilization continued to advance with like physical changes to accommodate its new uses. It is not necessary to trace the history of the theatre through its various vicissitudes to the period of the housed-in theatre of mediaeval Europe, and thence onward, to demonstrate that the seating arrangement of an almost prehistoric generation dictated the ultimate conformation of the classic hemicycle now in use.