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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 eponymous Arsacid dynasty of Parthia. 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 the Assyrians (under Ashurbanipal, at around 669–627 BC, the boundaries of the Assyrian Empire reached as far as Armenia & the Caucasus Mountains), Medes, Achaemenid Persians, Greeks, Parthians, Romans, Sassanid Persians, Byzantines, Arabs, Seljuks, Mongols, Ottomans, successive Iranian Safavids, Afsharids, and Qajars, and the Russians.

What made Armenia so easily invadable?
strategic location between two continents