Xerxes

Xerxes (クセルクセス, Kuserukusesu), alternatively romanized as Cselkcess in the Viz manga, was an ancient country that existed in the Great Desert to the east of Amestris four hundred years before the start of the series. Despite having had a remarkably advanced society for their era, the entire population of Xerxes was mysteriously left in the fragmented legends of neighboring countries.

History
Xerxes was a relatively peaceful, thriving land despite the harsh conditions of the desert that surrounded it and, at the time of its sudden disappearance, had a population of over a million people. The majority of the population was sustained by crops grown in the plantations of the suburbs. The water used day-to-day was taken from wells and the upper-class people wore shawls. The urban areas developed around domed temples and lively trade markets. Xerxes appears to have had a markedly intellectual culture that fostered written languages as well as longstanding philosophical and alchemical studies. In an age before modern construction materials, the people of this land had mastered the construction of stone and brick buildings ranging from simple stucco-coated homes to lavishly enormous palaces. Though slavery seems to have been a common practice, it was possible for slaves to rise out of thralldom through education, even going so far as to become members of high society, as intellectuals were considered part of Xerxes' upper echelon. Xerxes was also a centralized monarchy, with a King and royal court governing from the capital, a castle city in the center of the country.

Destruction
When a prominent alchemist within the King's court created a Homunculus with extensive arcane knowledge of alchemy, the aging monarch saw his chance to transcend his dreaded and inevitable death through immortality. The creature agreed to become the royal court's primary consul on the subject of alchemy-based immortality and persuaded the desperate king to construct an array that would encompass all of Xerxes and use all the people's souls to create a source of immortality. A large trench was dug according to the Homunculus' specifications, while the citizens were given the impression that their dutiful king had ordered the construction of irrigation canals to defend their crops against drought. Beginning with the northern town of Bonath, five towns around the circle were destroyed - the homes burned down and the people and livestock slaughtered - carving a crest of blood into the land. However, when it came time to activate the circle, it became immediately apparent that the Homunculus had deceived the court.



By providing slightly incorrect information and thus fashioning the array around himself and his caretaker instead of around the King, as he had claimed to have done, the Homunculus was able to cleverly steal the lives of Xerxes' citizens, royalty and his creator for himself and use them to create a pair of immortal bodies, each housing half of the nation's souls. Xerxes' entire population was wiped out instantly, leaving only the two immortals to survive as Human Philosopher's Stones. The two parted ways, leaving the dead country of Xerxes behind.

Aftermath
Over time Xerxes decayed into ruins and the circumstances of its destruction remained unknown to everyone besides Hohenheim and the Homunculus, besides a vague legend of it being destroyed in a single night by a Philosopher's stone which many were sceptical to believe.

The Homunculus, now known as "Father", would return to the remains of Xerxes centuries later to destroy the evidence of his sin; having his son Gluttony devour some of the Transmutation Circle inside the castle to keep others from realizing the truth behind the fall of Xerxes, and the fact that he planned to repeat the tragedy in Amestris.

In more modern times the ruins of Xerxes consist mainly of the decaying remnants of the king's castle and capital city; the famous, yet remote site acts as an oasis for travelers venturing across the Great Desert from Amestris to Xing or vice-versa. Additionally, the ruins serve as a haven in which a number of Ishvalan refugees have taken refuge in the years after the Ishval Civil War.

When Maria Ross was framed by Envy for Maes Hughes' death Roy Mustang used Xerxes to hide her after faking her death where Fu would to take her to Xing, in exchange for freeing Ling Yao from prison. Edward Elric would explore the ruins during this time and discover the remains of the Transmutation Circle within the castle, sparking suspicons due to his recent encounters with the Homuncli. When Edward, Ling and Envy were accidentally swalloed by Gluttony and stranded in the fake portal of Truth, Edward discovered the other half of the Xerxes Transmutation Circle's remains that Gluttony devoured centuries ago. With this Edward finally deduced that the Homuncli were behind Xerxes destruction and used it to create a Philosopher's stone.

Hohenheim would later tell Edward and Alphonse, (as well as Greed in Ling's body, Darius and Heinkel accompaying Edward at the time) the full account of Xerxes' destruction. At the end of the series Edward and Alphonse are the only living descendents of Xerxes and they, along with Ling, Darius and Heinkel, are the only living people to know the truth behind Xerxes' destruction.

Ethnic Characteristics
For the most part, Xerxesian people are characterized by having light complexions as well as gold-colored hair and eyes; however, there does seem to have been a minority of citizens with darker skin tones and similarly light-colored hair.

The 2003 Series
The nation of Xerxes is only mentioned briefly in episode 27, when Al and Ed study alchemy and talk about the risk in human transmutation and Al mentions "the country they say died in a single night". Ed is convinced that this story is just a fairytale, but refers to it as "The story of the Philosopher's Stone in the eastern desert", meaning they talk about Xerxes and not the Underground City beneath Central.

Due to the split between the manga and 2003 anime plot lines, the Underground City appears to have been a sort of parallel to Xerxes in the 2003 anime series, as its ancient civilization had been wiped out to create a Philosopher's Stone by Hohenheim of Light and Dante four hundred years before the start of the series and had been dragged underground so as to keep others from discovering the truth.

The Video Game Series
Siam-Sid is the former capital of the country of Lebis in the video game Fullmetal Alchemist 2: Curse of the Crimson Elixir. The former king of Lebis had attempted to create a perfect human being and the ritual involved therein, wiped out the entire civilization in a single night.

Lebis is most likely a misspelling of Rebis, an important concept in medieval alchemy, due to the translation from English to Japanese and then back again.

Trivia

 * As direct descendants of Van Hohenheim, the last living Xerxesian, both Edward Elric and Alphonse Elric are half Xerxesian on their father's side. Both brothers even share the features of Xerxesian people; golden hair, eyes and tan skin.
 * Judging from the architecture, style of dress and cultural similarities, it is more than likely that Xerxes is based on the civilization of the Persian Empire. This would also tie into the fact that much of the Fullmetal Alchemist canon is based on the Greek and Persian cultures (through Greek hermeneutics).
 * Xerxes could also be based on Plato's fictional thalassocratic civilization of Atlantis, based upon an equally fictional continent upon the Atlantic ocean. Plato highly fictionalized how the Greeks effectively foiled the second Persian invasion (480-479 BCE) into Athens' defeating the Atlantean conquerors. However, the Greek resistance & the whole Atlantis continent later violently sank into the ocean's depths by earthquakes & floods, leaving mere only a muddy shoal.
 * Coincidentally, Achaemenid Persia's capital Persepolis was burned to the ground overnight by the debauchery of Alexander the Great when he conquered the city. All that is left of Persepolis in modern times is columns and foundations in the sands, as so was Xerxes in Fullmetal Alchemist. However, Alexander's destruction against Persepolis (~330 BCE) happened long after Plato's death in 348-7 BCE, so it is doubtful that Plato meant Atlantis' destruction to be Achaemenid Persia's disintegration.
 * Similarly, the blonde, golden-eyed phenotype might be a reference to 19th and 20th centuries' pseudo-scientific occult traditions holding that the Aryan race migrated to India & Iran from a mythical island or continent Thule/Hyperborea/Atlantis located in the North Sea.
 * In reality, a minority of modern Indo-Iranian peoples still possess light hair & eye colors, just like the historical Iranic-speaking Scytho-Sarmatians (modern descendants: Yaghnobis & Ossetians). As their Proto-Indo-European ancestors from Yamna culture had a moderate skin tone, brown eyes, and dark hair, the lighter phenotypes might've originated from Old Europe's non-Indo-European speakers who intermixed with Yamnayan new-comers. As these mixed ancestors migrated to Central Asia & then Iran, India, Anatolia (Mitanni), they helped distribute both the darker & lighter phenotypes.


 * Xerxes was the name of the King who ruled the Persian Empire from 486-465 BC. His wife was Queen Amestris. King Xerxes was murdered by Artabanus, who then gave the position of power to his seven sons. According to Aristotle, Artabanus was then killed by Artaxerxes, son of Xerxes and Amestris.
 * This draws interesting parallels to FMA series, where the country of Xerxes was destroyed by Father. Father then created the seven homunculi, and gave the highest position of power in the country to one of his sons, and the other homunculi watched over the Amestrian cities. It is fitting, that Father, like Artabanus, was killed by Edward Elric, with a mother from Amestris, and a father from Xerxes. Like Artaxerxes, Ed avenged the Xerxesian people by dealing the final blow on Father.
 * In the Manga, the pronunciation of the word was written based on the Greek pronunciation of the Persian name, thus causing confusion to American translators. The name of the country is pronounced and written "Ku-se-ru-ku-se-su" in Japanese, prompting the publishers of the manga's English translation to incorrectly romanize the word as "Cselkcess". Though original Japanese fact books spell the name similarly, the 2009 anime series has rectified this mistake, displaying the word as "Xerxes". As such, the English dub reflects the realization based on the proper spelling. Incidentally, the English pronunciation of the word begins with a "z" sound in contrast to the original Greek.
 * Xerxes had a total population of 1,072,659 people.