Preslav (Civ6)/Civilopedia

Until it was fortified in the early 9th Century AD, Preslav was just a sleepy little Slavic settlement. But by the time of the coronation of Boris I, with his capital in nearby Pliska, it was an important strategic center and the seat of the Bulgar 'Ichirgu-boil,' commander of the capital’s garrison and de facto head of the kingdom’s military. The town also became a religious center when the Bulgars converted to Christianity in 864 and built a number of churches there.
But Preslav’s primary business was war. Once a pagan revolt was finally defeated in 892 and Boris appointed Simeon I as his successor, the decision was made to move the capital from Pliska to the much-more Christian Preslav. For the next 80 years, not only did the new capital become the political and military center of Bulgaria, but its cultural, artistic, and religious center as well. The walls were expanded and reinforced, and its barracks became the training ground for Bulgar delusions of grandeur.
Until, that is, the Bulgars were defeated by the Kievan prince Sviatoslav Igorevich and Preslav occupied. The ensuing war between Byzantium and Kiev left the city ravaged and nigh razed by the liberating Byzantine armies. A lesson in being beware of one’s allies. The Byzantines carried off the Bulgarian treasury, the royal jewels and regalia, and most of the royal library.
Preslav recovered some of its military importance in the first decades of the “Second Bulgarian Empire,” c. 1185. Indeed, it was – along with the fortress at Tarnovgrad – one of the joint seats of the kingdom under the co-rulers. But the strategic defensive position of Tarnovgrad proved better able to withstand outside threats. The Tartar raids of the 1270s drove off what citizens in Preslav survived; they built a new village of the same name a couple miles away, plundering the once-mighty walls for building materials.