Hrazdan () is a town and urban municipal community in Armenia serving as the administrative centre of Kotayk Province, located northeast of the capital Yerevan. As of the 2011 census, the population of the town is 41,875. It has lost a significant number of inhabitants since the 1989 census reported 59,000 people. During the Soviet period, Hrazdan was one of the highly industrialized centres of the Armenian SSR. The prelacy of the Diocese of Kotayk of the Armenian Apostolic Church is headquartered in Hrazdan. Etymology The town is named after the Hrazdan River which flows through the town from north to south. The name Hrazdan itself is derived from the Middle-Persian name Frazdān which is related to the Zoroastrian mythology. Frazdān is the name of the lake mentioned in the Avesta while referring to Goshtasb's war with two of its enemies. Armenians were predominantly Zoroastrian before embracing Christianity, and Zoroastrian names were maintained in the geography of Armenia. History Ancient history and Middle Ages Historically, the territory of Hrazdan is associated with the historic Kotayk canton of Ayrarat province of Ancient Armenia. According to Ptolemy, Kotayk was directly ruled by the Arsacid kings of Armenia during the 1st and 2nd centuries AD. Later between the 5th and 7th centuries, the region was granted to the Kamsarakan and Amatuni families, under the Persian rule. Between the 7th and 9th centuries, Armenia suffered from the Arab Islamic occupation. By the end of the 9th century, the region became part of the newly established Bagratid Kingdom of Armenia. Between the 11th and 15th centuries, the region suffered from the Seljuk, Mongol, Ag Qoyunlu and Kara Koyunlu invasions, respectively. 16th to 19th centuries At the beginning of the 16th century, the territory became part of the Erivan Beglarbegi within the Safavid Persia. During the first half of the 18th century, the territory became part of the Erivan Khanate under the rule of the Afsharid dynasty and later under the Qajar dynasty of Persia. It remained under the Persian rule until 1827-1828, when Eastern Armenia was ceded to the Russian Empire as a result of the Russo-Persian War of 1826–28 and the signing of the Treaty of Turkmenchay. 20th century and beyond With the fall of the Russian Empire and as a result of the decisive Armenian victory over the Turks in the battles of Sardarabad, Abaran, and Gharakilisa, the region became part of the