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.
Azerbaijan–Iran relations
For almost all of her history, the territory of the present-day Republic of Azerbaijan was a part of the various Iranian/Persian empires or Persianate empires, specifically during the reign of dynasties such as Median, Achaemenid, Parthians, Sassanid, the Shirvanshah, various dynasties of the Iranian Intermezzo, the Kara Koyunlu, the Ak Koyunlu, the Safavids, the Afsharids, the Zands, and the Qajars. The South Caucasus, in general, has been influenced by Iranian culture for thousands of years. In the course of the 19th century, following the occupation of the Caucasus by Russian troops during the Russo-Persian War (1804-1813) and Russo-Persian War (1826-1828), Qajar Iran was forced to cede what is now Azerbaijan, alongside Georgia, Dagestan, and Armenia to Imperial Russia under the terms of the treaties of Gulistan and Turkmenchay. Due to historical, cultural, ethnical, and religious ties, the Republic of Azerbaijan is considered as a part of Greater Iran.