Shadow Marches

Capital: Zarash’ak (unofficial)
Hallmarks: Eberron dragonshards, herbs
When most people think of the Shadow Marches, they imagine a fetid backwater where illiterate humans mingle with orcs and other foul creatures, practicing strange rites by the light of the moons. While flawed, this vision isn’t entirely inaccurate. The Shadow Marches are a desolate land of swamps and moors. The homeland of the orcs, the Marches were scarred in the ancient conflict with the daelkyr. The fiends left twisted creatures and aberrations in the swamps, and sowed seeds of madness that linger to this day. There are indeed moonlit rituals in the Marches: some to honor the daelkyr, others to maintain the wards that keep them trapped in Khyber.
Humans came to the Marches long ago, refugees fleeing a war in the distant land of Sarlona. Over time the two cultures merged, forming the Marches as they exist today.
The Marches had little contact with the Kingdom of Galifar or the east until a few hundred years ago, when a House Sivis expedition made two discoveries: the region contained valuable dragonshards, and a number of clans had manifested the Dragonmark of Finding. This led to the foundation of House Tharashk, as these clans joined together to master the economic potential of their mark and leverage their mineral wealth.
The Shadow Marches aren’t a nation. No one voice speaks for the clans and tribes, and most of the tribes have no interest in dealing with outsiders. House Tharashk is the largest faction in the region, and their city of Zarash’ak is the center for commerce.
House Tharashk is the main point of contact between the Shadow Marches and the outside world. Tharashk aside, the region remains a collection of tribes and cultists following their ancient traditions in the shadows of the swamps.

Interesting Things About the Shadow Marches
The untamed Shadow Marches are filled with mysteries. Relics of the daelkyr rest undisturbed in the depths of the swamps, along with foul monsters and druidic shrines.
The Marches are the birthplace of the druidic tradition of the Gatekeepers. Long ago, this sect defeated the vile daelkyr; today, its last champions continue to protect Eberron from aberrations and other extraplanar threats.
Even in defeat, the daelkyr sowed seeds of madness in the Marches. Followers of the Cults of the Dragon Below remain scattered across the region. Some of these cults work with mind flayers and other aberrations. Others have no evil intent but are driven by dangerous delusions.

Aftermath of the Last War
The Shadow Marches aren’t a nation, and the region wasn’t recognized by the Treaty of Thronehold. Most Marchers have little interest in the outside world. Marcher tribes don’t know the names or number of the nations beyond the swamps, let alone that they were at war. However, as House Tharashk gains power and influence in the world beyond the swamps, it has increased its presence in its homeland. The house has expanded Zarash’ak dramatically over the last decade and is working on transforming other towns into cities. This has caused tension with a number of tribes. And House Tharashk’s mining operations and its urban expansion always run the risk of disrupting Gatekeeper seals and unleashing ancient evils bound beneath the Marches.