The Bjni village is located in the Kotayk district. Beginning with the 10th century, the political role of Bjni’s Pahlavuni dynasty flourished. In the 11th century Bjni became the fort-city, and the residence of Vasak Holum Pahlavuni. Vasak reconstructed the fort and in 1020 was able to withstand and change the nomadic tribe’s invasion plans. In 1066 elections were held in Bjni for the Catholicos. In 1045 Grigor Magistros handed over Bjni, together with some other homeland properties to Byzantium, and in exchange received cities and villages in Mijagetk. In 1072 Bjni fell to the Seljuk-Turks and faced a period of destruction and plunder. In 1201 the united Armenian-Georgian army freed Bjni and made it the royal residence of Atabek Zakaryan Avag.
In the 13-14th centuries Bjni became the residence of the Archbishop of the Ararat province, he was one of the four archbishops of eastern Armenia and his vote played a crucial role in the election of the Catholicos. In 1478 Bjni was mentioned as the «divine and impregnable mansion».
In 1648 by the order of Catholicos Pilipos Aghbaketsi, Bjni’s church was reconstructed. In 1929 the Armenian Committee of the Preservation of the Historical Monuments conducted excavation works and discovered tombs belonging to the late iron era. The discovered items are still today held in the Armenian State Historical Museum. The ruins of this old city are located on the higher elevated plateau of the right shore of the Hrazdan River.
On the eastern side of Bjni the St.Sargis church sits on top of a hill (7th century), with its cruciform vaulted construction made from shaved tuff. It was reconstructed once again in 1970. On the plateau there is a fort that was constructed by the Pahlavuni kings, which for centuries was the main fortification of the Upper Nig province, and it was from here that all access to Bjni was monitored. The fort is protected by high-rising cliffs from the south, the east and partially from the west. On the north and west side stood a pyramid wall, which is now half-destroyed.
Inside the fortress much is in ruins and traces of the constructions still visible. In 1031 the son of Vasak Pahlavuni (the head of the fort) Grigor Magistros, built the St. Astvatzatzin (Holy Virgin) church (now preserved). It is of the ‘vaulted hall’ type with entrances both from the west and south. It has an apse on its eastern part, and 32 drums. Unique and original, this church has stone shelves built 5m high stretching around the walls. It is assumed that numerous manuscripts written in the Bjni monastery were put on these shelves.
From the south there is an attached chapel (13th century), which has a cross-stone on its eastern walls’ hollow section, which is a clear evidence that in Bjni stone masters existed and functioned. In 17th century the church was made to be surrounded by a rectangular circumference. It was once again reconstructed in 1947.