Armenia converted to Christianity in 301 AD under King Tiridates III, making it the first state to adopt Christianity as an official religion. Gregory the Illuminator, who had been imprisoned for 13 years in a pit at Khor Virap, emerged to baptize the king and establish the Armenian Apostolic Church. Etchmiadzin Cathedral was built in 303 AD and remains the mother cathedral of the Armenian Church. The church developed independently from both Rome and Constantinople, rejecting the Council of Chalcedon in 451 and maintaining distinct liturgical practices and theological positions. Armenian Christianity shaped the nation's identity through subsequent centuries of foreign domination, serving as the primary distinguishing feature when political independence disappeared.
The Armenian alphabet was created in 405 AD by Mesrop Mashtots, a monk and theologian who designed 36 letters to translate the Bible into Armenian. Before this invention, Armenians used Greek, Persian, and Syriac scripts for writing. The alphabet enabled a golden age of literature in the 5th century, often called the period of translators, when religious and philosophical texts entered Armenian. The Matenadaran in Yerevan holds over 17,000 manuscripts, some dating to the 5th century, including illuminated Bibles, scientific treatises, and historical chronicles. The alphabet expanded to 38 letters in the 12th century with the addition of two characters for foreign loan words.
Urartu, a kingdom centered in the Armenian Highlands, dominated the region from the 9th to 6th centuries BC. The Urartian king Argishti I founded Erebuni fortress in 782 BC on a hilltop overlooking the Ararat Plain, establishing what would become Yerevan. Cuneiform inscriptions at the site document construction details and the king's conquest campaigns. Urartu fell to the Median Empire around 590 BC. The Armenian language, part of the Indo-European family, had already been spoken in the region, but Armenian ethnogenesis as a distinct people occurred during the period after Urartu's collapse, mixing indigenous populations with incoming groups.
The Artaxiad dynasty ruled from 189 BC to 12 AD, with Tigranes the Great expanding Armenian territory to its maximum extent between 95 and 66 BC. At its peak, Tigranes controlled an empire stretching from the Caspian Sea to the Mediterranean, including parts of modern Syria and Lebanon. He founded a new capital called Tigranocerta, whose exact location remains disputed among historians. Roman general Lucullus defeated Tigranes in 69 BC, reducing Armenia to a client state caught between Rome and Parthia. Armenia became a buffer zone where the two empires installed competing kings, a pattern that continued for centuries with successive powers.
Arab armies conquered Armenia in the 7th century, incorporating it into the Caliphate while allowing the Armenian Church and nakharar noble families to maintain internal authority. The Bagratid dynasty established an independent Armenian kingdom in 885 when Ashot I received recognition from both the Caliph and Byzantine Emperor. The Bagratid capital at Ani, near the modern Turkish border, grew to a population estimated between 100,000 and 200,000 by the 11th century, with churches, palaces, and sophisticated water systems. Byzantine annexation in 1045 ended the kingdom, and Seljuk Turk invasions in the 1060s devastated the Armenian plateau. Many Armenians migrated south, establishing the Armenian Kingdom of Cilicia on the Mediterranean coast, which survived until 1375.
The Ottoman Empire gained control of Eastern Armenia by 1555 through treaties with Safavid Persia, while Persia held the eastern portions. This partition lasted until Russia defeated Persia in 1828, acquiring territories that form most of modern Armenia through the Treaty of Turkmenchay. Armenians in the Ottoman Empire faced increasing pressure in the 19th century as nationalism grew and reforms threatened traditional power structures. Sultan Abdul Hamid II ordered massacres of Armenians in 1894-1896, killing an estimated 100,000 to 300,000 people. The Young Turk revolution of 1908 initially raised Armenian hopes for equality, but deteriorated into suspicion and violence.
The Armenian Genocide began on April 24, 1915, when Ottoman authorities arrested approximately 250 Armenian intellectuals and community leaders in Constantinople. The Committee of Union and Progress government, facing military losses in World War I, ordered the deportation of Armenians from eastern provinces under the pretext of military necessity. Deportation convoys marched into the Syrian desert, where most died from starvation, dehydration, and organized killings. Estimates of the death toll range from 600,000 to 1.5 million, with most scholars accepting figures between 800,000 and 1.2 million. The genocide dispersed Armenians globally, creating a large diaspora that now exceeds the population of Armenia itself.