Heard of by many, the political organisation of the lands of the Rhoyne between the lands of Qohor, Norvos and Volantis is shrouded in mystery, ruled appropriately by His Grey Grace, the Shrouded Lord, Prince of the Sorrows. This individual is rumored to be the source of greyscale, the undead Prince Garin, the ruler of a band of pirates, and a magical statue in the style of Pygmalion. However, documents of the Library of Sunspear tell a different story, and also, the true story.
In fact, the Princes of Sorrows are actually a junior branch of House Nymeros Martell, and, while contact with Dorne was lost over a century ago, there are records in sunspear telling of the irredentist campaigns of Princess Rhoyne in Essos, hoping to reestablish the old lands of the Rhoynar under the descendants of Nymeria. Princess Rhoyne was one of a kind. She was the last practitioner of the water magic of the Rhoynar.
When Princess Rhoyne came to power, she was the first ruler of Dorne to practice magic. Growing up she had idolised Nymeria, and even learned of the old magics of the Rhoynar as they were starting to die out. She grew up during an epidemic of Greyscale. House Yronwood had been decimated by it and as it worked its way across the coast of Dorne, it reached sunspear. Her father himself, Prince of Dorne, went out and fought against the stonemen surging over Westeros. He was partially responsible for the end of the epidemic, and was wounded, and at one point dragged along the ground by a stoneman, yet, he did not become infected with the disease. Interestingly for Rhoyne, very few people of Dorne were afflicted with the disease. She discovered the None of My Countrymen clause of greyscale, the disease governed by the curse of Garin. Inspired by this, she began to plan her first act for when she would rule Dorne.
When the time came and Rhoyne Ascended to the seat of Dorne, she gathered those lords and men willing to go and risk it all. She was only able to get one ship's worth. The advertising had called for warriors and settlers who were descended from the Rhoynar. The majority of them were from the Shadow City, which had begun to develop soon after the arrival of the Rhoynar. A mæster came too, as well as Princess Rhoyne's younger brother and apprentice, Ænthnie.
Princess Rhoyne's expedition sailed up the Rhoynish delta on the same path Nymeria used to travel out, and then used her magic to allow passage past Volon Therys and all of the other Volantene towns of the river, expecting that the free cities wouldn't take too kindly to a random Westerosi noble coming in and founding a new competing country. During this time, Rhoyne had been finishing up teaching Ænthnie water magic, creating spectacles in the open ocean. After the underwater section was done, the two mages cleared the mist so they could see where they were going.
By the time they reached Chroyane, Ænthnie had completed his training and reached an arrangement with Rhoyne who would go on to Ny Sar and set herself up in Nymeria's old palace. Returning home felt good, but Rhoyne was called away less than a year into the Nymerian Restoration, as house Qorgyle had rebelled against them, and she had to go back to put it down, and was rendered unable to return, though contact was maintained with the Mæster in Ny Sar, but once he died, all ties were lost. Over time, the population grew and grew. Magic became a valuable skill.
However, it is hard to build a functioning society in the middle of a cloud that afflicts a lot of outsiders with an infectious curse. Sure, a mist that can curse invaders is great for defense, but not so good for merchants. Also, while marauding cursed mad monsters is great for dealing with invading armies, it is not so good for encouraging trade, and when emissaries were sent to the various neighboring countries, Volantis in particular was very hostile, and started sending stonemen up the river to try to infect the New Rhoynar. With Qohor, however, an agreement was made on setting the border where the Qhoyne met the Darkwash. Qohor, to a certain extent could sympathise with the dream that Princess Rhoyne had, as their Aurion had something not too different. With Norvos, however things were different.
Without any special empathy, Norvos declared war, and while Norvos won on land, Ænthnie and the Sorrowmen won consistently at sea, because they had magic. The war resulted in an uneasy truce, where the Nymeroses control the flat while Norvos controls the highlands.
To this day, the Descendants of Ænthnie Nymeros Martel reside in the Palace of Sorrows, known among the residents of the Sorrows as Nymeros Palace. Despite the rumors, Qohor still trades with Nymer to this day, Volantis still tries to infect them, and Nymer sends privateers to go after Norvosian and Volantine ships. The result is that the place appears to be lawless but isn't simply because there are so many licensed pirates. The population of Nymer has expanded a lot since Princess Rhoyne brought them there. Recently, Nymer has been importing Dragons from the freehold, and maintains active trade with Tyria, Oros, and even Old Valyria, travelling underwater by means of magic.
As with the closeness with Valyria, Tyria, Oros, and Rhyos, would suggest Ny Sar and Chroyane have very different views of magic to Westeros. In Ny Sar and Chroyane, the cities of Nymer, magic is a survival skill, as it is for any traders of the Smoking sea. Their magic gives the merchants from Nymer a unique ability to trade with the Valyrian Peninsula, since they can sail the smoking sea by taking outside water with them. Nymer also has even entered into a mutual defence pact with Valyria, Tyria, Oros and Rhyos, as all of them are worried about attacks from various other countries. These attacks could be for many reasons, including fear of invasion, especially by Volantis.
The education system of Nymer teaches the Rhoynish language because it is necessary to use for magic. It has also since become the common tongue of the region, and usage of Common has diminished to the point of a neglegable speaking population.
In terms of soft power, Nymer exerts influence only on the Valyrian Empire founded by Aurion I of Qohor; in both countries a similar relationship is had with magic, and they are, save for with Mantarys, the city of monsters, through the Valyrian port of Oros across the smoking sea. However, Nymer is a larger trading partner, and has a large amount of interest in Tyria, with a full on school teaching water magic, and conversely, in Lhyvu, in the southern Sorrows, the Valyrians have established a school of water magic, however, there are currently no Dracaris valyrainus in Nymer. However, ships have been seen traveling up the Lhorulu and lightning storms have been growing more common in Chroyane and the rest of Nymer, and sightings of electric blue flying serpents have also been reported as of late as far as Volantis which has seen a particular uptick in lightning strikes.