This helmet was designed in 1915 by Latvian inventor and British citizen John Leopold Brodie:

Image: National Army Museum

Made of steel, it was designed for mass production; the Brodie helmet, as it came to be called, was cut from a sheet in one piece, then pressed into shape. It was issued to Commonwealth forces, and later U.S. soldiers, during World War I.

This Chalcidian helmet was fabricated around 2,200 years earlier, sometime around 350-250 B.C., by a designer whose name we'll never know:

Made of bronze, it was worn into battle by Greek soldiers from the Chalcidice region. It is striking to see how much more ornate this object, which had to be painstakingly made by hand, is versus the mass-produced design above.

The helmet hews to form-follows-function. The brows are curved for the sake of visibility, with a widow's peak offering a few extra millimeters of protection. The cheek guards are actually hinged, making the helmet easier to don and doff. There are cutouts for the wearer's ears so that they can hear commands.

Then there's the most notable feature, which you're probably wondering about: What's with the drinking straws up top, what function could they possibly serve?

The answer, surprisingly, is terror. Those tubes are actually "plume holders," meant to hold, get this, feathers.

"Feathers were popular embellishments on Chalcidian helmets, intended to intimidate enemies and show an association with Ares, the god of war, who is often depicted wearing a crested helmet," writes Christies, who auctioned the helmet off this month. "Both [of the ancient historians] Livy and Polybius make reference to aigrettes (horsehair crests and/or feathers) and their ability to create fear in battle."

"I am Ares, God of War, and I'll SHOVE THESE FEATHERS RIGHT UP YOUR @#*&%$"

This alternative Greek design, made around the same time as the Chalcidian helmet, is known as a Pilos helmet:

Less thought has been given here to human factors, with more focus given to decoration. The helmet has wings, for spiritually-invoked protection if not actual physical protection; they're a callback to Hermes, the messenger of the gods and protector of human heralds.

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What really caught my eye are the spiral plume holders.

Let's think about this for a second. Of the two plume holder designs in these two helmets, which is superior? I believe there's only one right answer.

I believe the spiral design is superior. Think of this: How are the feathers meant to be held in place, and remain in place during battle? It's not like they had zip-ties back then. With the tubular design, I assume they stuck the feather(s) in and poured melted wax from a candle into the tube to hold them in place. With the spiral design, you could conceivably weave the quill in and out of the helix, holding it in place with friction.

An alternative possibility is that they jammed so many feathers into each holder that friction held them all there, like a fistful of straws.

Whatever method they used, it's difficult to imagine all of the feathers remaining in place during a pitched battle. But it is fun to imagine whatever silly pre-game ritual they used to affix the feathers prior to battle. (Also: Do you reckon the soldiers had to source the feathers themselves, or that a quartermaster handed them all out?)

The Pilos design also features this crazy curlicue on the top.

GoPro mount? No, the description says that it, too, is a plume holder. I can't fathom how it was used.

Both of these helmets, by the way, fetched eye-watering sums at auction. The Chalcidian went for $283,500, and the Pilos sold for $214,200.