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.
Afghanistan–Iran relations
Afghanistan shares a relatively long history with Iran (called Persia in the West before 1935). When the Safavid dynasty was founded in Persia, part of what is now Afghanistan was ruled by the Khanate of Bukhara and Babur from Kabulistan. The first Iranian Safavid Shah Shah Ismail I quickly expanded his empire in all directions, in which he also conquered large parts of nowadays Afghanistan. For centuries they ruled the region and the Safavids didn't have any problems at first ruling the eastern most territories of their empire, but their policy towards non-Shia subjects became worse and worse over time. Wars began between the Shia Safavids and the larger Sunnis, particularly in the Old Kandahar region. By the late 17th century, the Safavids were heavily declining. They had appointed their Georgian subject Gurgin Khan as governor of Kandahar in order to forcefully convert the Afghans from Sunni Islam to Shia Islam. This went with much oppression and violence.