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.
Greater Iran
Greater Iran (, ) is a term used to refer to the regions of the Caucasus, West Asia, Central Asia, and parts of South Asia that have significant Iranian cultural influence due to having been either long historically ruled by the various imperial dynasties of Persian Empire (such as those of the Medes, Achaemenids, Parthians, Sassanians, Samanids, Safavids, and Afsharids and the Qajars), having considerable aspects of Persian culture due to extensive contact with the various imperial dynasties of Iran (e.g., those regions and peoples in the North Caucasus that were not under direct Iranian rule), or are simply nowadays still inhabited by a significant amount of Iranic peoples who patronize their respective cultures (as it goes for the western parts of South Asia, Bahrain and Tajikistan). It roughly corresponds to the territory on the Iranian plateau and its bordering plains. The Encyclopædia Iranica uses the term "Iranian Cultural Continent" for this region.