Strygos

Strygos was a human empire built within the Strygos Valley by the mad shaman Kadon, then ruled by the Strigoi Vampires from the city Mourkain, before it fell to the machinations of Neferata and the onslaught of Greenskins.

History
Although the Greenskins have conquered much of the northern and eastern Badlands as their own, they are still competing with the Human tribes that still held sway to the territories to the south. In the very distant past, the territories that would comprise much of the southern Badlands was originally dominated by many Human tribes who were subjects to the Kings of Nehekhara following the conquest of King Setep of Khemri some 1,200 years before the birth of Sigmar and the founding of the Empire of Man. However, following the destruction of Nehekhara at the hands of Nagash, the tribes of Humans living around the Badlands were united under the charismatic and powerful leadership of a local Shaman named Kadon.

As a young man, Kadon was a Shaman, and also the young leader of the Lodringen Tribe. The rise of power and popularity of Kadon came about when the Shaman found the deceased and bloated remains of Alcadizaar the Conqueror, the last King of Nehekhara upon the banks of the Blind River. From his hand lay an ominous crown of Iron known in history as the Crown of Sorcery. Filled with the corrupting influence of the crown, Kadon commanded his people to build a magnificent tomb for Alcadizaar and around that tomb, their settlement evolved into a city that came to be called Mourkain. As both he and his people began to grow powerful, Kadon began a campaign of conquest against the Greenskin tribes of the northern Badlands, pushing the Greenskins out of their territories and claiming all the land from Mourkain to the Black Gulf as his own.

With the covert assistance of Ushoran, first of the Strigoi bloodline of Vampires, Kadon saw the city grow over the years into an empire which, at its height, stretched from the Marshes of Madness all the way to the Black Gulf. Kadon developed and refined the art of necromancy to further Nagash's work, and he created several powerful magical artefacts dedicated to the raising and controlling of the Undead. After some time, Kadon was replaced by Ushoran as the new leader of Styrgos. The rapid expansion of the Strygos civilisation drove many Greenskins out of their settlements in the Badlands and into the World's Edge Mountains.

The bellicose Orcs could not ignore this encroachment onto their territory forever. Eventually, the Orc tribes united in a massive Waaagh! under a mighty Orcish Warlord named Dork Redeye and marched upon the city of Mourkain with a huge and imposing army. Despite being well-schooled in the Necromantic arts, both the Strigany people and the Strigoi Vampire were no match for the amassed might of the fearsome Greenskins and were slaughtered wholesale, their cities and villages burned to the ground. A massive battle was fought outside the gates of Mourkain itself, during which Ushoran was slain by the Orc warboss, although his crown was taken by his chief acolyte and spirited away before Ushoran's army was defeated. The Strygos Empire was destroyed entirely, so much so that the only indication of it ever existing are the eerie cursed ruins that haunt the Marsh of Madness. With their homelands lost, the Strigany people headed north into the Old World, living a nomadic existence amongst the Human kingdoms that have been established there.

Source

 * Blood in the Badlands (supplement)
 * pg. 6