The Núr'uir

Once, Archaios was all but united under the banner of a sprawling Elven Empire called the Núr'uir. But despite the peoples' natural longevity, their kingdom eventually succumbed to the ebb and flow of time like any other.
At their apex, the Núr'uir ruled over The Mithral Spire and had settlements as far east as Dor'loss, and as far north as Mir'Heled. Such a wide reach resulted in a number of bouts of internal strife; some more world-shaking than others. Early on, the high elves of the Núr'uir split with the wood elves of The Sylvan Realms based on a disagreement of the Empire's expansive ways. Later, a full on civil war led to the banishment of the Drow from the surface world. 
The elves of the Núr'uir also butted heads several times with external factions. On multiple occasions, they clashed with The Dwarves of Skeggaria as they attempted to muscle in on their subterranean realms. They also engaged with and repelled an invasion of extradimmensional Mindflayers and surived a resurgence of draconic campaigns. They even picked fights with The Former in a bid to unravel their magical secrets. 
Despite their propensity for conflict, the Núr'uir persisted for many ages, making strides and innovations in arcane theory that is still widely used to this day. However, all good things must come to an end, and somewhere around 2500 AC, the Núr'uir Empire collapsed. The exact cause of this has been lost to time, but the speed and totality with which the collapse occured have left countless scholars scratching their head at what could have caused such a thing. 
Despite the collapse, Núr'uir culture still persists in small pockets across the land. Most notably, the elves of Mir'Heled consider themselves to be the last of the Núr'uir, though the elves of kingdoms like Dor'Loss, Sui'lad, and Brytnia trace their origins back to the old empire.

Culture

Common Customs, traditions and rituals

Magical tattoos play a heavy roll in Núr'uir society. While some higher class elves get them just for show, many of them serve practical purposes beyond aesthetics. As the ink used to create these tattoos are imbued with magic, the cost of creating one can range from as little as 50 gold to tens of thousands of gold and years of preparation (the quality of the ink is what affects the overall value of the tattoo, rather than the quantity).
These tattoos can grant hosts of different abilities, from increasing ones durability, to granting resistance to certain types of damage, to conjuring magical weapons, to allowing one to walk through walls for a time. The recipe for these magical inks is a closely guarded secret and thus very few people beyond Mir'Heled have ever even heard of such creations.

Coming of Age Rites

Almost every youth of Mir'Heled engages in a pilgrimage of sorts called a Peregrination, in which a newly "adult" elf ventures out beyond the city to see the world beyond. These trips last anywhere from 6 months to several centuries. Some elves never return at all. Those that do return though, always do so with new experience, perspective, or knowledge to share with the city.
The purpose of the Peregrination is to go and find something new and relevant to bring before Sae'l He'ru, thus adding to the collective knowledge and understanding of the elven people and ensuring that they continue to grow and prosper.

Common Myths and Legends

While the high elves of Aeturnum used to worship a whole host of deities, since their empire was smashed to bits (with no help from the so-called "gods") the elves have turned their reverence towards a singular being: Sae'l He'ru.

Sae'l He'ru is believed to be the collected consciousness and wisdom of every penitent elf that ever lived. It is considered the highest honor to die and join consciousness with Sae'l, who is said to only accept the souls of elves who bring new perspective and information. Because of this, many Aeturnum elves become scholars of the arcane who spend their lives attempting to unravel the mysteries of the weave.

Governance

Mir'Heled is steeped in deep-rooted tradition. For untold millennia, the Nur'uir have governed themselves by bloodline monarchy. Because of their long lifespans and dedication to tradition, dynasties can last for thousands of years. As such, the Nur'uir have only had a handful of different bloodlines ruling the kingdom. The regent also keeps the council of a number of prominent family heads, usually no more than 6. Should a king or queen ever pass without an heir, it is this council who decides on a new ruler from among their number.

Calendar

Naturally, the elves do not adhere to the same calendar as most human cultures, though it does follow a similar scheme as the Antecean calendar, broken into 3 ages: a prehistoric age, the age of the empire, and the new age. In the elven calendar, the current age simply uses "modern" as shorthand (i.e., 1216 EP is considered 2350 modern). The age of the empire, which uses "gold" as short-hand, spanned 4,489 years and encapsulates the creation of the Mithral Spire in Kentro to the first fall of Lar'Nimloth.
The ancient calendar counts in reverse like the Antecean version and uses "ancient" as its shorthand. For reference, Mir'Heled was founded in 396 ancient, making it well over 7,000 years old, one of the oldest elven cities ever created and by far the oldest still standing today.

Bladesingers

The elite of Mir'Heled's sentinels are the esoteric Bladesingers, wizards trained in an ancient form of spellcasting and swordplay. Within the overarching order of bladesinging, there are several distinct styles pertaining to the type of weapon the wizard uses. All bladesingers bear a magical tattoo that serves as a focus for their bladesong and represents the school of training they hail from:

• Lion. Specializes in longswords and rapiers
• Tiger. Specializes in shortswords and scimitars
• Eagle. Specializes in battle axes
• Crane. Specializes in reach weapons like quarterstaffs, glaives, and spears
• Viper. Specializes in flexible weapons like flails, whips, and chains.