Rome had two great _Circuses_ which were destined for races, for these were the national games of the Romans from the earliest times. The most ancient, the _ludi magni Romani_, which were traced back to the time of Tarquinius Priscus, were established for the patrician burgesses; but besides these there existed, likewise, from very ancient times, _ludi plebeii_, a very remarkable instance of the manner in which in all Roman institutions the populus and the plebs stood by the side of each other. Down to the latest period, these two kinds of games were never held in the same place. In the early times the plebeians had no share whatever in the _ludi Romani_. In the Circus Maximus the places were assigned to the populus according to curiae, _ad spectacula facienda_,[27] as scaffoldings are still erected on both sides of the Corso at the time of the races. The _Circus Maximus_ may have had its present extent from the very first, for it could not be very small on account of the chariot races, but it was not as high as afterwards. A greater height became necessary when, instead of the small number of the populus and their clients, the whole Roman people took part in the spectacle; the plebeians may indeed not have been excluded in the early times, but they had no places assigned to them. This Circus between the Palatine and Aventine cannot have been laid out before the building of the Cloacae, and the carrying through of the Marrana, since previously the whole was a marsh. At present the sewers must be blocked up, for in digging to the depth of a few feet nothing but morass and marshy ground appears. The splendid obelisk which now stands before the church of the Lateran, was dug out there as late as the sixteenth century: and there can be no doubt that valuable treasures of art are still buried there. The Circus occupied the whole length of the valley, now la Via de’ Cerci. That form of it, of which we have a description, was planned and undertaken by Caesar, and probably completed by Augustus, for it is inconceivable that the short duration of Caesar’s dictatorship should have sufficed for it. It is said to have contained room for 300,000 men, the seats rising in terraces above one another as in the Colosseum. On the outside, it presented rows of porticoes one above the other, the lowest one being occupied by shops or stalls. In the middle ages, the Circus Maximus was used as a fortress.