Narrator: Caesar lives in a time when most countries are ruled by kings.

Rome prides itself on being a republic.

Here, elected representatives share power.

Holland: Five centuries earlier, the Roman people had risen up and expelled their king, a haughty tyrant, and brought the monarchy to an end.

And the republic was designed precisely with the aim of ensuring that there would never be a king again.

And there's a kind of collective memory among the Roman people, a deep-seated dread of tyranny.

Andrew Wallace-Hadrill: The basic principle of the republic is that no individual can dominate the system.

It's a fundamental part of their rhetoric.

We just don't do monarchy.

Narrator: At the heart of the republic is the Senate, the seat of government presided over by an elite body of wealthy aristocratic men.

Shushma Malik: Rome was not a democracy as we might recognize it now.

But living in a republic in Rome gives the people more participation in how Rome makes decisions, and the republican system of government essentially means that you have an advisory body, which is the Senate, made up of the best men, what the Romans thought of as an aristocracy.

Wallace-Hadrill: Senators are elected in very sharp and bitter competition with each other, and Caesar has been making his way up the ladder.

Narrator: Caesar's ambition is to maneuver his way up the strict hierarchy of the Senate.

The higher the rank, the fiercer the competition.

Right now, Caesar's a mid-ranking aedile.

The ultimate prize is the consulship, a year-long post shared by two men.

Wallace-Hadrill: To make your way in politics in Rome brings you status.

And the key Roman word for that is dignitas, your dignity.

Caesar says repeatedly that dignity was dearer to him than life itself.

"My reputation is everything."

Holland: And so, to win the consulship, this is what dignitas is all about.

That is the kind of the sweetest fulfillment for a Roman.

I mean, this is why, basically, Caesar wants to be pontifex maximus.

It's not an end.

It's a steppingstone to an end.