Ancient Armenia lasted from Alexander’s wake until 428 AD
Greater Armenia spanned 331 BC to 428 AD under Orontid, Artaxiad and Arsacid dynasties. Born from an Achaemenid satrapy on Urartu’s ruins, it peaked under Tigranes the Great in the first century BC—then spent centuries as the buffer Rome and Parthia could not leave alone.
Before any Armenian kingdom, the highlands around Lake Van belonged to Urartu, which rivalled Assyria until the Medes conquered it in 590 BC. The Achaemenid Persians then ran the region as a province, and the Orontid family governed it as satraps for three centuries. Alexander's victory at Gaugamela in 331 BC ended Persian rule, and after his death Orontes III declared independence, even fighting off a Thessalian commander who coveted the gold mines of Sper.
The last Orontid, Orontes IV, was overthrown around 200 BC by Artaxias I, a Seleucid commander possibly related to the old line. Once Rome beat the Seleucids at Magnesia in 190 BC, Artaxias built an independent Hellenistic state, united the highlands and founded a new capital, Artaxata, near the Araxes. His successor Tigranes the Great fielded an army that one ancient account put at 120,000 foot soldiers plus heavy cavalry and mounted archers, figures probably inflated by writers on the losing side. Plutarch credited Armenian bowmen with lethal shots at 200 metres.
Rome caught up in 66 BC, when Pompey beat Armenia's ally Mithridates VI of Pontus and turned the kingdom into a client state. Mark Antony invaded in 34 BC; in 20 BC Augustus struck a truce with Parthia that made Armenia a buffer. Both empires backed rival kings, and Nero's general Corbulo campaigned there from 55 to 63. The Parthian prince Tiridates I was crowned in 52, founding an Armenian Arsacid line, and Trajan briefly made the country a Roman province from 114 to 118.
Sassanid Persia occupied Armenia in 252, but Roman armies installed Tiridates III in 287. Persuaded by Gregory the Illuminator, he adopted Christianity as the state religion. Division between Byzantium and Persia followed in 387, and independent statehood lapsed until the Bagratids revived it in the 9th century.
Source: Kingdom of Armenia (antiquity)
