Pliska was the place where two events of extreme importance for the Bulgarian identity took place -
the converting to Christianity, (year 864) and the returning of the disciples of the Cyril and Methodius brothers (year 886) who launched the spreading of the 'cyrilic' alphabet in Bulgaria.
Pliska, the capital of medieval Bulgaria, represented the fortified residency of the Bulgarian rulers during the pagan period (the end of 7th century ) and three decades after the adoption of the Christianity as a state religion.
In 893 the capital of Bulgaria was moved to Preslav. In the 10th and 11th century after the foreign invasions of the Russians, Byzantines and later the attacks of the 'late nomads' Pechenegs and Uzes that followed caused the abandoning of the former khan residency.