List of ancient great powers
The Sassanid Empire is the name used for the fourth Iranian dynasty, and the second Persian Empire (226–651). The empire's territory encompassed all of today's Iran, Iraq, Armenia, Afghanistan, eastern parts of Turkey, and parts of Syria, Pakistan, and large parts of Caucasia, Central Asia and Arabia. During Khosrow II's rule in 590–628 Egypt, Jordan, Palestine, Lebanon were also briefly annexed to the Empire, as well as far west as western Asia Minor. The Sassanid era, encompassing the length of the Late Antiquity period, is considered to be one of the most important and influential historical periods in Iran. In many ways the Sassanid period witnessed the highest achievement of Persian civilization. The empire is furthermore known for being the arch-rival of the neighboring Roman–Byzantine Empire for a period of over 400 years. As the Parthians were replaced by the Sassanids, they carried on the already century long lasting Roman–Persian Wars, which would eventually become the longest conflict in human history.
Armenia
In the next centuries, Armenia was in the Persian Empire's sphere of influence during the reign of Tiridates I, the founder of the Arsacid dynasty of Armenia, which itself was a branch of the Parthian Empire. Throughout its history, the kingdom of Armenia enjoyed both periods of independence and periods of autonomy subject to contemporary empires. Its strategic location between two continents has subjected it to invasions by many peoples, including Assyria (under Ashurbanipal, at around 669–627 BC, the boundaries of Assyria reached as far as Armenia and the Caucasus Mountains), Medes, Achaemenid Empire, Greeks, Parthians, Romans, Sasanian Empire, Byzantine Empire, Arabs, Seljuk Empire, Mongols, Ottoman Empire, the successive Safavid, Afsharid, and Qajar dynasties of Iran, and the Russians.