This state encompassing most of the southern mountain region of Grenwal has, for its longest time, shined through its military prowess. When the Osé Sultanate once tried to press forward into central Liwilai, Oesterholm and its capital of Veduna held on long enough to repel its forces. The family of the Archduke is also known for marrying into noble houses and royal families all across Liwilai, giving the Archduchy a ton of bargaining power; more recently, though not part of Oesterholm itself, this clever alliance-building has given the Archduchy ownership of the Kingdom of Hugan, making Oesterholm's Archduke also Hugan's current King.
However, all this luster is starting to fade, especially with its slow adoption of the new technological innovations that are making waves across the world. It's becoming increasingly obvious that the Kingdom of Branjeprus is starting to outshine Oesterholm in many ways, even beating it in several wars over the past centuries, which has led to a bit of bitterness. Most notably, the title of Emperor of Grenwal, which was held by the previous Oesterholmian Archduke, but now is being held by the King of Branjeprus, is a point of contention.