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.
Iranians in Russia
People from the former and contemporary boundaries of Iran have a long history in the territory of what is modern-day Russia, stretching back thousands of years. Throughout history, the Caucasus region was usually incorporated into the Iranian world, and large parts of it were ruled by empires based in modern-day Iran for a time span encompassing many centuries, or were under its direct influence. From the early 16th century up to including the early 19th century, Transcaucasia and a part of the North Caucasus (namely Dagestan), were ruled by the successive Safavid, Afsharid, and Qajar dynasties of Iran, and made up part of the latters concept for centuries. In the course of the 19th century, by the Treaty of Gulistan of 1813 and the Treaty of Turkmenchay of 1828, Iran ceded the region to Russia. Ever since, the Dagestan region still makes up part of Russia.