5. It was built during the monarchy by the fifth king, LuciusTarquiniusPiscus (616 BC to 579 BC) During the Republic and Empire, it became increasingly adorned and its size increased. At its greatest size, it could hold more than 270,000 spectators
7. The emperor Trajan later added another 5000 seats, and expanded the emperor's seating to increase his public visibility during the games.
8. The circus arena was divided into two tracks by a long central barrier (spina), marked at the ends with conical turning-posts and decorated with Augusts’ obelisk and other monuments
10. The obelisk was originally from Heliopolis, Egypt and brought to Rome by Augustus around 10 BC and erected on the spina of the Circus Maximus. It was found in 1587 in two pieces and re-erected by Pope Sixtus V in the Piazza del Popolo in 1589 as part of his urban plan.
11. At each end of the spina there would be a set of seven metal dolphins (in honor of Neptune) and a set of seven eggs. These would be taken down one at a time as the chariots lapped round the track.
12. During the chariot races, four, six, eight, or twelve teams of horses competed, beginning at the wider end of the circus at the starting gate Starting Gates
13. Image #3 - The Circus Maximus and Emporer's Palace - reconstructed on Google Earth
14. Chariot racing was often dangerous to both driver and horse as they frequently suffered serious injury and even death, but generated strong spectator enthusiasm.
15. The chariot driver's clothing was color-coded according to his “faction”, which would help distant spectators to keep track of the race's progress.
16. There were originally just two factions, White and Red, sacred to winter and summer respectively. Later, there were four factions, the Red, White, Green, and Blue. Each team could have up to three chariots each in a race.
17. Members of the same team often collaborated with each other against the other teams, for example to force them to crash into the spina (a legal and encouraged tactic). Drivers could switch teams, much like athletes can be traded to different teams today.