Empires fight to get the ability to tax an ever-greater territory.

The ancient European empires fought themselves all the time because they wanted to be the ones to own the mercantile network in the Mediterranean so that they can tax it.

The definition of a smuggler or a pirate is one who doesn’t want to give you half their stuff. Empires used navies to stop this.

This is where we got the term free port - a port where you don’t need to give up half your stuff.

-- an excerpt from the Saylor Series Episode 2 - the Rise of Man through the Dark and Steel Ages, its 2-minute version can be found here https://www.2minutebitcoin.org/blog/saylor-series-episode-2-the-rise-of-man-through-the-dark-and-steel-ages-robert-breedlove