A lot of people have questions about the war that took place in Kalos 3,000 years before the events of X and Y. The first, and most obvious, is that France wasn't around 3,000 years ago, so is this even a reference to a real war? Many assume it's the War of the Roses and thus involves England / Galar as the other participant (merely time-displaced, as is Game Freak's wont), but after some study I found this can't be the case.
For starters, let's look at some imagery of the Kalos War from the games:
The conflict is divided into two clear sides, left and right. On the left side, we have:
-Honedge
-Gyarados
-Solrock
-Lunatone
-Steelix
-Salamence
-Talonflame
-Rhyperior
-Floette (AZ's Pokemon!)
-Golurk
And on the right side, we have:
-Noivern
-Magnemite
-Magneton
-Aggron
-Weavile
-Abomasnow
-Bisharp
All of these are catchable in modern-day Kalos, either as pre-evolutions or as themselves (the only possible exception being Aggron, as Aron/Lairon are exclusive to X.) This would indicate that both forces used native Pokemon to conduct the war, rather than Pokemon imported from outside the region.
In addition, human soldiers are present on either side, behind the battling Pokemon. Here are some closeups:
While these pictures are not terribly revealing of outfit, skin tone or other discerning factors, something they do reveal are some very particular styles of helmets.
The style on the left is Corinthian, used by Ancient Greek hoplites (soldiers) to identify themselves and thus avoid friendly fire, as well as a status or rank signifier:
While this is a modern reconstruction, the general shape is recognizable enough.
The style on the right, however, is more difficult to place. It clearly features a plume in the shape of a horsetail, which is used by a variety of cultures. Closest matches appear to be the lamellar helmet (left), used by medieval Europeans during the Early Middle Ages (~500 - 1000 CE) and possibly the Imperial Gallic helmet series (right, but more on that later).
And, if we assume Corinthian versus Gallic styles, suddenly the entire Kalos war makes perfect sense.
According to Junichi Masuda, Kalos' name was taken from Greek "κάλλος" or "beauty", and Greek settlers established the trading port of Massalia and subsequent cities as a loose collection of city-states (much like the Athenian or Spartan territories) following conflicts with the native Gallic regions in and after 600 BCE (or around 2,600 years prior to the present day - rounded, that's 3,000 years ago). 'Gaul', which comprised territories that would one day become modern France, was divided into five regions according to the Romans who conquered it later: Celtica (most of the upper half of France and most of Switzerland), Belgica (the northern tip of France and all of Belgium), Aquitana (the southwestern corner), Narbonensis (the partially Greek-occupied southeastern corner), and Gallia Cisalpina (east of modern-day France, is actually mostly Italy).
Massalia was located in Gallia Narbonensis along the southern coast, and founded at least 12 cities, including some which would survive to the present day: Nice, Antibes, Monaco, Le Brusc, Agde, Aleria, and of course the original location of Massalia itself - Marseille:
Despite these cities having autonomous or semi-autonomous rule (with at least two minting their own currency), prior writings in the 1960's by Charles Eben ascribing this as an "empire" are now seriously questioned, given that Massalia had very little chora (directly controlled agricultural territory). What is known is that it eventually came to be regarded as a place of culture by the Romans, who would send children there for education, and a disgraceful settlement by mainland Greeks, who regarded the long, perfumed robes and tying up of the hair that Massalians adopted as disgustingly effeminate.
"But wait," you might be saying. "This is nowhere near Geosenge Town, the location of the Ultimate Weapon. What would a Greek city-state 'king' like AZ be doing all the way over there?
Geosenge Town marked with a red triangle, as well as Kalos itself for reference.
Geosenge Town would be territory firmly occupied by the largest of the Gallic regions - Celtica. However, the war was never stated to take place on AZ's home territory, and in fact is implied to have taken place somewhere far away by the official dialogue:
"A war began.
The man's beloved Pokémon took part in the war.
Several years passed.
He was given a tiny box."
While little is known about initial conflict between Gaul and Massalia, the Greek outpost would have at least been considered a credible threat. AZ may have intentionally built and fired the weapon where a large-scale conflict was taking place in order to cause as many casualties as possible, and would have traveled to the location of the war to do so. Prior to this, AZ's home territory appears to be largely unknown - while a painting apparently depicting him (or reminding the player character of him) can be found in the Parfum Palace on Route 6, and a younger AZ can be seen in a mural in Lumiose Museum, the only area of Kalos explorable by the player near where Massalia should be are the player's hometown, Vaniville, and Kiloude City (the postgame Friend Safari area), neither of which appear to have any connection to AZ. However, since the southern coast of Kalos does not appear to be at all visible, it can be assumed that these areas are actually in the mainland and thus wouldn't be inside Massalia's territory.
TL;DR - sometime before 2,600 years ago, a fight broke out between the invading Greek city-state led by AZ and the native Gallic (Kalosian?) settlements. Because AZ used the Ultimate Weapon to cause so much casualty, the war was effectively ended, leaving a power vacuum during which AZ's city-state was able to conquer or significantly influence what would one day become modern Kalos. This means that the Kalos War is not only period-accurate, it's also (semi) accurate to real-world history and does not appear to involve any known outside regions.
Incidentally, would this make AZ's 'real' name AZ or AΩ?
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