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.
History of the Kurds
The Kurdish region of Iran has been a part of the country since ancient times. Nearly all of Kurdistan was part of the Iranian Empire until its western part was lost during the wars against the Ottoman Empire. Following the dissolution of the Ottoman Empire, at the Paris Conferences in 1919, Tehran demanded various territories including Turkish Kurdistan, Mosul, and even Diyarbakır, but these demands were quickly rejected by Western powers. Instead, the Kurdish area was divided by modern Turkey, Syria and Iraq. Today, the Kurds inhabit mostly north western Iran known as Iranian Kurdistan but also parts of Khorasan, and constitute approximately 7–10% of Iran's overall population (6.5–7.9 million), compared to 10.6% (2 million) in 1956 or 8% (800 thousand) in 1850.