North of the Shieldlands on the western coast of the Inner Sea lies the land of Myrmidia. Here the soil is rocky but rich, and the climate is pleasant. It is peopled by a copper-skinned, warlike folk who bore the brunt of the force of the beastman legions during the Zaharan War. As casualties mounted, the then-king Myr made a pact with forces unspeakable, that his bloodline would have many strong sons to stand against the beastmen. His prayers were answered, but perhaps not quite as he had intended; his line was indeed fecund, but from that day forth three out of every four children of his blood were born male. These sons also matured with incredible speed, reaching adulthood at 12 years of age. When the Zaharan War was won, the descendants of Myr quickly came to dominate the other human cultures of the area, forcing them into servitude as serfs (or helots in their tongue), and a proper kingdom was established with Myr's children and their descendants as the armed nobility.
When Myr himself died, though, his many heirs began vying for the throne, each real contender with the backing of a city-state. Shortly thereafter, two unfortunate side effects of Myr's Bargain were discovered. First, Myr's sons were discovered to have a short lifetime commensurate with their rapid maturation; they began dying of old age at around 40 years, and none are known to have survived past 75. This meant that even as they warred for the throne, Myr's successors were themselves dying and their own children fought over their city-states. Second, the shortage of women of Myr's blood put the bloodline in peril, as violence between Myrmidians over "true-blooded" women intensified.
In time Myr's eldest daughter, Iana, grew sick of the civil war, assassination attempts, and marriage proposals and, in proper Myrmidian fashion, decided to re-unify what she considered her rightful kingdom by force. She gathered a group of maidens sympathetic to her cause and vanished into the hills. Several years of training later, she emerged with a cadre of fanatically loyal amazons skilled in spear and bow, and set about retaking cities and extracting oaths of fealty. Time was on her side; as female descendants of Myr neither matured nor aged faster than any other human, she and her warriors had the lifespan for grand strategic maneuvers and could often simply outlive her opposition. She was ultimately successful, and installed herself as the first in a long line of amazon queens which rules to this day. Iana instituted a matriarchal caste system, with female descendants of Myr as the ruling class, male descendants as a warrior caste, and the helots at the bottom. The amazons themselves exist as a kind of bridge; any woman, even a helot or foreigner, may join the amazons, but most are found wanting, and only amazons of Myr's blood are eligible for queenship. After Iana's death, the amazons developed into a sort of ancestor or personal cult worshiping her as a goddess of order, planning, maidens, and law (think kind of Athena meets Artemis; also, game note - "amazon" is a variant bladedancer class). Likewise, the male descendants of Myr worship Myr himself as a paternal deity of war, strength, and vigor. Both groups partake in hero worship for other minor deified and demideified successful ancestors as well. The helots worship a wide variety of pre-Zaharan agricultural gods, who are disdained by the Myrmidians.
As a culture, the Myrmidians remain athletic, warlike, and fiercely independent. Unable to wage war against each other by edict of the queen, the warriors of the city-states instead content themselves with mercenary service to foreigners, raiding parties into the wilderness of Zahar and the Shieldlands, and skirmishes against raiding Skanucks and beastmen. Indeed, mercenaries are one of the region's chief exports, and these myrmidons as they are called are its primary emissaries to the rest of the world. They are widely renowned as soldiers for their discipline, vigor, and skill, and are widely believed to be the best medium infantry that money can hire. They favor round shields embossed with faces and symbols of deities, monsters, or animals, and fight with long spears; many also carry short swords or daggers, but they consider bows unmanly and dishonorable (as those are favored weapons of the amazons). They are usually armored in a breastplate, greaves, and plumed helm, eschewing heavier armor in favor of speed. The extent of Myrmidian metallurgy is bronze and wrought iron; they favor bronze, as the Myrmidian hills are rich in tin and copper.
When not engaged in warfare, the Myrmidians enjoy footraces, spear-throwing, and wrestling. These are, in fact, one of the primary means of selecting mates for noble Myrmidian women, alongside mock combats and tales of great deeds in battle. With a ruthlessly competitive warrior class and a dearth of noblewomen, this ensures that only the most fit of Myr's descendants continue his line. Likewise, among the amazons comprising Myrmidia's administrative nobility, contests of wits, piety, art, philosophy, and fitness are used to determine who gains in rank. This rule applies even to the queenship, though here divine revelation is the most common means of determining the succession. The Myrmidians generally do not mate for life as a result of the large difference in lifespans between males and females. Some noblewomen hold a single tournament and keep a consort indefinitely, while others hold yearly tournaments and change consorts regularly (though repeat winners are not unknown).
The soil of Myrmidia is good, but rocky; tilling and plowing is quite a pain, so instead orchards and vineyards are the primary form of agriculture. Grapes and olives are local favorites, with barley being the primary grain grown in available flat areas. Herding of sheep and goats are also widespread, as are fishing and diving for urchins along the coast. The Myrmidians favor loose, flowing clothes of light wool and sandals.
Myrmidia is well known for its bright, fruity wines and olive oils, and possesses a small fleet of merchant vessels which transport these across the Inner Sea. Pirates are generally loathe to attack such vessels, for the myrmidons are fierce fighters at sea, being unburdened by heavy armor. The queen also maintains a fleet of triremes with skilled crews for transporting large forces quickly (as is sometimes necessary for the pacification of rebellious cities), as well as for engaging Skanuck war fleets at sea when necessary. The Skanucks and the Myrmidians keep a reasonably good humor in such matters; a Skanuck sailor might be aboard a trading ship one season and a raider the next, and friendships made in port sometimes persist even during battle. Gambling debts do too, though, and the Myrmidians are uniformly poor gamblers and liars. The Sorosi and the Myrmidians maintain something of a cold naval war for control of the western Inner Sea; the Sorosi possess more and faster sloops, but they are smaller and less disciplines, while the Myrmidian triremes can crush any one Sorosi vessel, but are trouble engaging. It is widely held that much Sorosi pirate activity in the western Inner Sea is in fact at the behest of the crown as spoiling and scouting measures against the Myrmidian navy.
As noted above, the Sorosi and the Skanucks are both common trading partners of the Myrmidians. The marble dwarves to the west, while close, desire little that the Myrmidians produce, though their steel is greatly valued and demands exorbitant prices. The Myrmidians regard the Shieldlanders as a combination of vagabonds and country bumpkins; many a myrmidon has considered conquering the Shieldlands, but most have decided it wasn't worth putting up with the people. The Dardanians come to Myrmidia most often as employers seeking mercenaries, though their secrecy and love of bloodsport are widely considered distasteful. Myrmidian views on the Talasi are conflicted; while they dislike the Talasi penchant for wizardry, viewing it as weak, the Talasi are one of their primary suppliers of wood and share in the Ianan cult. Likewise, the Urdukhar are religious rivals, as Urduk is the center of the Ashtari bladedancer cult (considered by the amazons to be a rowdy bunch of temple harlots with swords, while the Ashtari consider the Ianans prudes and cowards for fighting with bows). The Myrmidians know of the Sajuk horsemen, and are glad that distance and terrain provide a natural defense against them; their first mercenary engagements against the Sajuk went poorly, and forced the development of a longer style of pike and more coherent formations to counter this foreign cavalry advantage.
In sum: Sparta, but ruled by amazons with divine backing. A good place for fighter or bladedancer PCs to be from. Also good for picking up trade goods, hiring mercenaries, and non-violent contests for a temporarily elevated / noble position. This is, however, a bad place to try to commit crimes (highly mobile, widespread warrior population? Yeeeah... On the plus side, the punishment might just be banishment, which isn't so bad), and also a tough place to try to carve out a kingdom (for that, try the Shieldlands to the south or Skandia to the north).