As the Imperium's borders slowly receded after the devastation of the First Blight and the subsequently barbarian invasion, many outposts in the area, known today as the Free Marches, were cut off from centers of power. Numerous warlords tried consolidating the region into a single kingdom, but resistance prevailed. Emerius held out for almost a century until it fell to a slave revolt in 25 Ancient. It was not the first such revolt Emerius suffered, but it was the last.
It started when an Alamarri slave named Radun began earning popularity and power by pushing for better conditions. Radun's growing influence prevented the magisters from touching him, but eventually they had him poisoned. Furious, a group of Radun's supporters stormed the Gallows and were massacred, and so began a bloody yearlong rebellion.
The city burned, and wealthy Hightown was sacked. The magisters hung before cheering crowds. Emerius assumed the new name of Kirkwall, "kirk" meaning "black," after its jet stone cliffs. The new city plunged into anarchy for over a decade, and its defenses fell into ruin. Kirkwall has been conquered many times since, the city's own independence suffering since the freeing of its slaves.