Mark Gagnon

He also standardized weights and measures and coinage across the empire.

He built the famous Royal Road, a highway stretching roughly 1600 miles from Sardis in western Turkey all the way to Susa in modern day Iran.

And a royal messenger could travel the entire length in about a week using this relay system of fresh horses and riders.

So as a result, a message could go from the Aegean coast to Susa in roughly seven days.

And this is something that no other empire on Earth could match at the time.

Even Herodotus, an ancient Greek historian, was blown away by this.

He even wrote, Now think about that.

If you're able to move information and, you know,

money and other really important things for running an empire across these massive distances faster than other people, you're just going to be able to grow faster.

And now if this system sounds familiar to you, it's because the United States Postal Service literally adopted a version of those words and their unofficial motto, inspired by a description of the Persian mail system from 2500 years ago.

Literally, the U.S.

Postal Service, like the Pony Express type vibe, they were borrowing that message that Herodotus wrote about the Persians in their own messaging.

It's crazy.

And now, in addition to all that, Darius built Perzopolis.

Now, Perzopolis wasn't a capital in the traditional sense.

The empire had several administrative centers, including Susa, Babylon, and a bunch of other places.

But Perzopolis was the ceremonial heart of the empire.

It was where the king received tribute from all the nations under his rule, where the grand festivals were, and where the sheer power of Persia was put on display for the world to see.

Darius began construction around 518 BC, and the complex was still being expanded when Xerxes actually took the throne.

Now, Xerxes was born around 518 BC, roughly the same year that Persepolis was founded.