This first of four pods on the Colosseum offers a general overview of the structure, including its architecture and the materials used to build it. We also consider why the Flavian Emperors chose to build it where they did, right where there had been a beautiful water feature of Nero’s sprawling “Golden House.” We raise but do not yet address the question of what to think about those who took such delight in the cruel events staged in the Colosseum.

Show Notes

We get ready for the Colosseum by making a quick stop at the Theater of Marcellus, for this theater was built 80 years before the Colosseum, and its features were then replicated in the Colosseum. An amphitheater is essentially a double theater, and both the Theater of Marcellus and the Colosseum employ stacked stories of stone arches to support seating, though the one has three stories, while the other has four. Both take advantage of the attractiveness the rows of arches, whose lightness reduces the amount of stone needed and the mass pressing down on the foundation.

The Theater of Marcellus, showing both original arches to the left and modern substitutes on the right. Above are some very nice condos!

The main alternative to an arched opening is one with a horizontal beam, which is called post and lintel construction. (The beam is also called an architrave.) Among the advantages of the arch is that stone is strongest when supported from below, as a column is, but it is less strong when over a void, as a beam is.

Here on the Portico of Octavia, we see columns joined with a beam or architrave, not arches, such as the Colosseum used. The triangle above the architrave is called a pediment, and you can see here that it was filled in with miscellaneous chunks of stone to stabilize it in the Middle Ages.

Both buildings also use the same building materials:

  • travertine, an off-white or yellowish stone seen all over Rome and quarried just to the east of the city;
  • tufa or “tuff,” which is the tan or brown stone we also see all over Rome; and
  • bricks of various shapes, which have proved so useful because of the wonderful Roman cement that bonds them together.

The main secret to this cement is pozzolana, a volcanic ash that turns up in various deposits around Rome. It reacts chemically with lime mortars, and enables them to set more quickly and bond more tightly.

Both also used marble and stucco for decoration, but the one has mostly been seized and the other worn away.

It is pleasant and useful to walk patiently around the Colosseum the night before entering. As is illustrated in our logo, the outer ring wall is “notched.” That is, it looks higher in some places than in others, and this is simply because about half of the outermost wall is no longer in place. Less of the Colosseum is intact than you might imagine without giving it a good look. When, how, and why ancient Rome was demolished is question to which we will return more than once.

Bricks fill in an arched opening to stabilize the weakened structure of the Colosseum

While doing our circumnavigation, we consider who built it, why they did so, and where the money came from. Related to the question of Vespasian’s political reasons for building the Colosseum is the fact that it is located within the area of Nero’s absurdly vast and opulent “Golden House” (or Domus Aurea). This also included a colossal statue of himself, which was the alleged reason the Flavian Amphitheater was renamed “the Colosseum.” We note the location of its eventual base on the northwest side of Colosseum, toward the Temple of Venus and Rome.

That there was previously a lake at this spot in Nero’s “house” complicated the challenge of draining the area around it, but large drainage channels, which have been explored by archeologists in scuba gear, help explain how Roman architects met this challenge. We also note the Ludus Magnus outside the south side of the Colosseum, which was a training school and residence for gladiators. This gives us the opportunity to think about the logistics needed to put on the games, which required trained and somehow willing fighters, and healthy wild beasts from the four corners of the earth. We note also features of the exterior that were used to hold the adjustable “dome” or sunshade (the velarium) in place.

A look at the exterior also show lots and lots of pockmarks where one large stone joins another. Explaining why they are there sheds light on how times changed in the Middle Ages. It does not indicate how many embellishments were removed, probably including 160 large statues in the arches on the second and third stories.

On the inside, it is even easier to see that the Colosseum is ovoid or elliptical, not circular. It turns out that all the over 200 amphitheaters of the Roman Empire were similarly shaped. Why, I wonder, since it would be easier to build a circle. And if we go to the top level, we can see that the Colosseum is located in a sort of hollow, surrounded by low hills, which block the view of most other parts of the city. This only increased the need for large underground drains.

Also inside, we note the several signs of the Christian reuse of the Colosseum, which changed over the centuries. In just the last century, there was a sort of tug of war over the large cross that is conspicuously present. The new and anticlerical Italy of the Risorgimento had removed one like it as soon as it came to power, but Mussolini’s new Fascist government was seeking to improve relations with the Catholic Church in the 1920’s, and it put back a replacement in 1926, preparatory to signing the Lateran Pact in 1929.

A cross added to the Colosseum during the Middle Ages. An inscription adds a promise of reduced time in purgatory for those who kissed the cross.

To the dismay of botanists, the New Italy also removed the rich abundance and variety of plants and even trees that had grown up with their roots in the stone of the amphitheater. Some small descendants of these still grow there, and if you look around, you might find acanthus, which is featured in carved capitals of the Corinthian order.

Other observations to make on the inside include honeycomb of ruins that would have been covered by the arena floor and might help you imagine the cages that would have contained wild animals and the elevators that would carry men, beasts, and elaborate stage sets to the arena floor.

The pagan Romans loved these games; the Christian Romans must have hated them. And if compassion were not sufficient to have brought them to an end, their high cost and logistical challenges would have achieved the same result.

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