The top priority of Vespasian, the first Flavian Emperor, was to erase Nero's Domus Aurea, built on the ruins of Nero's famous fire, and return the land to public use. By 72 AD, just four years after Nero's suicide, Vespasian had torn down most of the palace and started building the Flavian Amphitheater on the site of the "pond" in Nero's former courtyard. It is now popularly called the Colosseum after the colossal statue of Nero that had stood nearby. (The American spelling, "coliseum", is simply incorrect). Vespasian died right before the grand opening, and it was left to his popular son and successor, Titus, to preside at the inauguration of the uncompleted amphitheater in 80 AD. Contemporary accounts speak of 100 days of gladiatorial games with thousands of animals and gladiators nobly facing slaughter before the 50 thousand or so spectators at morning and afternoon sessions. Construction and decoration continued for several more years.
The core of the Colosseum is relatively soft and porous tufa, but bricks and several grades of aggregate concrete were used where strength was needed. The exterior of the structure was clad in sculpted white travertine, which was attached to the core by iron bars. Some of the iron bars were mined out in later centuries, and that's why a large part of the exterior collapsed. Stone was also later removed from the site. There were originally three levels of arches, with engaged Doric, Ionic, and Corinthian pillars separating 80 arches on each level. The fourth level, with square composite pilasters, was added in about 230 AD when Emperor Alexander Severus expanded the structure.
The interior decoration varied with the status of the seating areas. Fine marbles were used for the Emperor's box and for the area to its immediate right for the Vestals and their escorts. VIPs, foreign guests of the Emperor, and court favorites sat to the Emperor's left. Senators had ringside seats, and right behind them were the "knights" (equites). Citizens and freedmen sat behind the equites. Slaves and women stood near the top as befitted their low social status. Cheaper seats were undecorated and made with cheaper materials. The ring was floored with wood covered with sand and sometimes with earth, rocks, trees, and other plantings as parts of elaborate settings for the games. Under the floor there were passageways, ramps, and rooms, but most of what is now seen dates from later periods. Awnings strung high above the audience by the imperial navy provided shade.
Nobody got in without a ticket, but tickets were free. You went to the games, showed your credentials, and were immediately given a ticket according to your social class. Tickets indicated which of the 80 lower arches you entered, how near the cheap seats you had to climb, the date on which the ticket was good, the name of the Editor, and the reason for the games. Tickets were good from the start of the day's festivities, about two hours after sunrise, until the last gladiator fell, and that might be after sunset if the Editor was generous. You could leave and return on the same ticket all day. Food was often included in the price of the ticket (that is, also free), and valiant efforts were made to keep the restrooms clean. At the end of the day, the stadium could be emptied rapidly, an important consideration considering that the audience, by that time, had seen slaughter and was really not much more than a bloody-minded mob.
Almost everyone went and enjoyed the day. Think of emotions aroused by "professional wrestling", bullfighting, boxing, NHL hockey in recent years, American football, rugby, and other modern blood sports.
P.S. -- Julius Caesar was the first Julio-Claudian. After pursuing Pompey around the Mediterranean and after his famous liaison with Cleopatra, he finally got back to Rome late in 45 BC but was killed on March 15 of the next year. He was followed by Augustus, Tiberius, Caligula, Claudius, and Nero who self-destructed in 68 AD.
Titus' own reactions to the opening games are not recorded although as "Editor" (the sponsor who announced the spectacle before the people -- that's what editor means) he should have been there at least to say a few words before every session, and he should also have been available for life-and-death decisions. He probably enjoyed the show: many of the participants were prisoners he had captured in the Middle East.
Lions 10, Christians 0. Christians were occasionally killed off by wild animals or forced to fight to the death, but that was really a small and, by all accounts, the most boring part of any festivities. Modern religious authorities say that maybe 10,000 Christians were martyred in several waves of persecution. Hundreds of thousands of non-Christians (millions if you believe the larger estimates) also died. The slaughter of such "criminal elements" was always scheduled around mid-day, when most of the audience was outside grabbing a snack.
An "inauguration" was the process by which "augurs" (priests) interpreted the flight of birds before the beginning of any new enterprise.
Vestals were expected to come to all of the games -- part of the job -- and were permitted and even expected to have male escorts, with whom they might be quite publicly familiar. The only thing forbidden to them (with serious consequences: burial alive) was the actual sex act.
Everybody got the day off for "festivities" which were held on special days called festae by the end of the Empire there were 270 festae each year.
Recently, international archeologists and engineers tried to rig awnings over a much smaller amphitheater in Spain for a TV documentary. They couldn't do it, and having failed miserably, they decided that ancient accounts of the awnings hung by the Roman navy had to be incorrect. Any experience Mediterranean or Red Sea sailor could have told them how to do it.
Description from the Platner and Ashby Topographical Dictionary:
The Smith Dictionary Article on Amphitheaters:
Best modern description with diagrams, reconstructions, and pictures:
Lacus Curtius -- 151 Colosseum links:
Best Colosseum images from Maecenas:
Old and new images: http://www2.siba.fi/~kkoskim/rooma/pages/COLOSSEU.HTM
Seindal image collection: http://sights.seindal.dk/sight/262_Colosseum.html
P.S.: How should we spell this word? "Colosseum"
is supposedly based on the "fact" that the structure was so called after
the colossal statue of Nero/Appolo/Constantine (sequentially) that stood
nearby. "Colliseum" is supposedly based on the "fact" that the structure
was named after the nearby hill or ridge (a "coll" on which a temple of
Isis was said to have stood. Take your pick (or any of several other variants),
but be prepared for pedants to contradict you.