According to ancient Greek sources, the territory of Armenia under Achaemenid rule was divided into two administrative units (satrapies). For two centuries, Armenia has paid a large tribute with gold and horses to the Achaemenids, which testifies to the country’s economic prosperity.
Considering the military power of the Armenian dynasty of Yervandunis (Orontids), the Persian kings appointed their representatives as rulers of the Armenian lands. Yervandunis have become the vassals of the Persian kings.
Having become satraps, they received privileges at the Persian royal court, preserving the traditions of the Yervanduni family. The ruler of Armenia, Yervand, who was married to the royal daughter, occupied an important position in the Persian court.
In 401 BC, a 10,000-strong squad of Greek mercenaries, retreating from Mesopotamia to the Black Sea, crossed the territory of Armenia. The detachment was retreating after the death of the brother of the king of Persia who had hired a Greek detachment to seize the throne.
The detachment was headed by outstanding Greek writer, historian, and commander Xenophon, who would leave the most important information about this campaign in his book “Anabasis”.
Passing through the territory of Armenia, the Greek detachment went around cities, fortresses, and temples, avoiding unnecessary clashes. The mercenaries made their way through defenseless villages where they replenished their food reserves.
Xenophon left important information about an Armenian village, describing the village houses-dugouts which had two entrances – one for people and the other for livestock. Each village had its headman.
Source: History of the Armenian people in questions and answers (Russian-Armenian (Slavic) University)