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.
Iranian Azerbaijanis
Following the Russo-Persian Wars of 1804–13 and 1826–28, the territories of the Iranian Qajar dynasty in the Caucasus were forcefully ceded to the Russian Empire and the Treaty of Gulistan in 1813 and the Treaty of Turkmenchay in 1828 finalized the borders between the Russian Empire and Qajar Iran. The areas to the north of the river Aras, including the territory of the contemporary Republic of Azerbaijan, were Iranian territory until they were occupied by Russia over the course of the 19th century. The Russo-Persian Wars of the 19th century settled the modern-day boundary of Iran, stripping it of all its Caucasian territories and incorporating them into the Russian Empire. The eventual formation of the Azerbaijan Democratic Republic in 1918 established the territory of modern Azerbaijan.