Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
Drama - Theatre
Both as respects extent of production and influence over the public, the drama stood at the head of the poetry thus developed in Rome. In antiquity there was no permanent theatre with fixed admission-money; in Greece as in Rome the drama made its appearance only as an element in the annually-recurring or extraordinary amusements of the citizens. Among the measures by which the government counteracted or imagined that they counteracted that extension of the popular festivals which they justly regarded with anxiety, they refused to permit the erection of a stone building for a theatre.(10)
10. Such a building was, no doubt, constructed for the Apollinarian games in the Flaminian circus in 575 (Liv. xl. 51; Becker, Top. p. 605); but it was probably soon afterwards pulled down again (Tertull. de Spect. 10).
Instead of this there was erected for each festival a scaffolding of boards with a stage for the actors (-proscaenium-, -pulpitum-) and a decorated background (-scaena-); and in a semicircle in front of it was staked off the space for the spectators (-cavea-), which was merely sloped without steps or seats, so that, if the spectators had not chairs brought along with them, they squatted, reclined, or stood.(11)
11. In 599 there were still no seats in the theatre (Ritschl, Parerg. i. p. xviii. xx. 214; comp. Ribbeck, Trag. p. 285); but, as not only the authors of the Plautine prologues, but Plautus himself on various occasions, make allusions to a sitting audience (Mil. Glor. 82, 83; Aulul. iv. 9, 6; Triicul. ap. fin.; Epid. ap. fin.), most of the spectators must have brought stools with them or have seated themselves on the ground.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/3-14-literature-art.asp?pg=15