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 Khorasan
Khorasan (Middle Persian: ; "Xorāsān", ), sometimes called Greater Khorasan, is a historical region lying in northeast of Greater Persia, including part of Central Asia and Afghanistan. The name simply means "East, Orient" (literally "sunrise") and loosely includes the territory of the Sasanian Empire north-east of Persia proper. Early Islamic usage often regarded everywhere east of so-called Jibal or what was subsequently termed 'Iraq Ajami' (Persian Iraq), as being included in a vast and loosely-defined region of Khorasan, which might even extend to the Indus Valley and Sindh. During the Islamic period, Khorasan along with Persian Iraq were two important territories. The boundary between these two was the region surrounding the cities of Gurgan and Qumis (modern Damghan). In particular, the Ghaznavids, Seljuqs and Timurids divided their empires into Iraqi and Khorasani regions.