During the reign of the Bagratids, after the restoration of statehood, numerous military bases, fortresses and other fortifications were established in Armenia, which controlled the strategic-trade roads, provided the protection of the North-Eastern territory. The larger ones became castles of power, often turning into fortress cities. There was a strategically important stronghold in the Aghst Valley, Kayan Fortress, probably built in the early 9th century. In the X-XI centuries, during the reign of the Kyuriks, there was a guard fortress that protected the eastern borders of the kingdom. The people of the area took refuge here at the time of danger. In the XII-XIII centuries the importance of the fortress gradually increased and it became the residence of large landowners. The first medieval author mentions Hovhannes Draskhanakertsi Kayan Fortress. In 922, Sahak, the prince of Utik, who was at enmity with Ashot Yerkat, entered the Zorapor province belonging to the Bagratuni and captured its fortresses, of which only Kayan is mentioned by the historian.