♪♪ ♪♪ -More than 15 different classes of gladiators, distinguished by their weapons, armor, and fighting styles, fought inside the Colosseum.

♪♪ -Through their armor, through their weapons, they have advantages and disadvantages, strengths and weaknesses.

-One of the most popular battles was between two specific classes -- the retiarius versus the secutor.

-This is a fan favorite.

This is the retiarius.

He was the only one whose face you could see, and that made him human.

The thing about gladiator helmets is that they dehumanized the fighter.

He became more of a robot.

He didn't show expressions of pain.

Whereas the retiarius is us.

We can see him.

We can see his expressions.

-As a way of projecting authority over the Roman people, many classes of gladiators were inspired by the ancient enemies of Rome.

But by the time the Colosseum was inaugurated in 80 CE, most gladiators were professional athletes who chose to fight.

The retiarius was a newer class of gladiator.

Fighting without a helmet, he was an everyman, a simple fisherman.

-So, he has two weapons, which are pretty iconic.

He's got a trident over here and a net.

The net is a really a very dramatic piece of equipment.

You can imagine them swinging it in the middle of the arena, the people loving it.

-The retiarius had the advantage of mobility, but little protection, unlike his opponents.

-The secutor here is a tank.

He's got not only this massive helmet, which, if you look at it objectively, has a little bit of a fishlike quality -- small eye holes, a fin on the top.

And, so, we have a theme to the fight.

♪♪ This is a fight of nature.

Man versus nature.

The fish against the fisherman.

♪♪ -Man versus nature.

Rome against its enemies.

Gladiator fights were more than sporting contests.

They were a part of Rome's national identity.

-And it's the clash of these two -- who's going to win?

-- that makes it exciting for the Roman audience.

That's what it is.

It's a show.