Historically, the Duchy of Ioliérs has existed in a somewhat contentious relationship with its neighbors to the west over the Pireña. There are a few territories that straddle this natural boundary that both countries lay claim to, and there have been a few border wars that have escalated to the point that the Imperators have had to intervene.
Economically, the duchy is known for its wines and for its mines (located in the mountains). A cluster of blood-red grapes are in fact the sigil of the current reigning ducal House d’Vais.
The duchy is the site of several significant cathedrals and other holy sites in the history of the True Faith, and the Church’s presence is particularly strong here. However, the Deacons of this region have also been known to indulge in some practices and beliefs that dance along the edge of heresy, and for this reason the Council of Prelates has kept a very close eye on them. The universities, however, have been responsible for some of the most learned interpretations of the holy books, as well as significant discoveries in terms of philosophy, science, and agriculture.
As was the case with many of the other duchies, there once existed a powerful local nobility and people, known as the Rikarians, a largely-tribal people who had resisted the efforts of their Haransharin overlords to keep them in line. They largely continued to worship their own deities. While there had been some contact between these people and the powerful duchy of Alusium in the south (which even before the uprising that led to the forming of the Imperium had been exerting influence), for the most part they remained stubbornly out of tune with the rest of the other countries that would become the Imperium.
When the first Imperators solidified their power in the region by marrying their daughter Irene to one of the many local dynasties, she served as a bridge between the hybridized Alusine/Helleneian culture of her parents and the local culture of the Rikarians. So beloved was she that she would become almost a goddess among the common people and, despite the strict ban of the increasingly powerful Church on the veneration of anyone who was not formally recognized as a saint, she has remained a pervasive presence to this day.
The fusion of these two cultural traditions, combined with the relative peace and prosperity of the region, has given birth to a place where beauty, love, and the arts are the highest aspirations. For the Rikarians, despite their quarrels with one another, possessed a poetic soul, and their tales were filled with stories of chivalry, courtly romance, and the sweet things of life. This melded easily with the deliberate (and sometimes) cold approach to such things favoured by the newly-arrived Helleneian and Alusine noble class. The rash of intermarriages that occurred, not just among the upper classes but throughout the culture, ensured that within a few generations the process was largely complete.
The current Duchess of Ioliérs is one Blanche d’Vais. As one of the blood royal, she claims a seat on the highest tear of the Senate of Nobles. She has so far proven to be one of Talinissia’s more supportive allies in the Senate, though in recent years she has withdrawn to her own estates in her duchy to be with her grandchildren. She has five children, three sons and two daughters. (She maintains a very large network of spies and informants in both the capital and elsewhere, however). Her heir is Lord Imael, who has so far shown that he is content to rule his domains and not interfere with Imperial matters more than necessary.
Blanche d’Vais is also well known for her support of the Academy in Aionis as well as the one located in her own capital of Viente, and she has long been rumoured to be particularly enamoured of the more arcane branches of knowledge that are typically considered out of bounds for one of her station. In the more sinister whisperings, she is even supposed to have engaged in the forbidden dark arts of blood sacrifice, particularly as these might grant her the youth that seems to be slipping away from her (at the time of the events of the series she is nearly 70).
In terms of historical analogues in our own world, Ioliérs is similar to the courts of Navarre and of the courts of love in Aquitaine.