Humanities › History & Culture The Longevity of the Persian Empire Share Flipboard Email Print Heritage Images / Getty Images History & Culture Ancient History and Culture Figures & Events Ancient Languages Greece Egypt Asia Rome Mythology & Religion American History African American History African History Asian History European History Genealogy Inventions Latin American History Medieval & Renaissance History Military History The 20th Century Women's History View More By N.S. Gill Ancient History and Latin Expert M.A., Linguistics, University of Minnesota B.A., Latin, University of Minnesota N.S. Gill is a Latinist, writer, and teacher of ancient history and Latin. She has been featured by NPR and National Geographic for her ancient history expertise. our editorial process N.S. Gill Updated November 22, 2019 The original Persian (or Achaemenid) empire, as established by Cyrus the Great in the 6th century B.C., only lasted approximately 200 years until the death of Darius III in 330 B.C., following his defeat by Alexander the Great. The core territories of the empire were then ruled by Macedonian dynasties, primarily the Seleucids, until the late 2nd century BC. During the early 2nd century B.C., however, the Parthians (who were not Persians but rather descended from a branch of the Scythians) set up a new kingdom in eastern Iran, originally in a breakaway province of the Seleucid empire. Over the next half-century, they gradually took over much of the rest of what had once been Persian-controlled territory, adding Media, Persia, and Babylonia to their holdings. Roman writers of the early imperial period sometimes refer to this or that emperor going to war with "Persia", but this is really a poetic or archaic way of referring to the Parthian kingdom. Sassanid Dynasty The Parthians (also referred to as the Arsacid dynasty) remained in control until the early 3rd century A.D., but by that time their state was seriously weakened by in-fighting and they were overthrown by the native Persian Sassanid dynasty, who were militant Zoroastrians. According to Herodian, the Sassanids laid claim to all the territory once ruled by the Achaemenids (much of which was now in Roman hands) and, at least for propaganda purposes, decided to pretend that the 550+ years since the death of Darius III had never happened. They continued to whittle away at Roman territory for the next 400 years, eventually coming to control most of the provinces once ruled by Cyrus et al. This all fell apart, however, when the Roman emperor Heraclius launched a successful counter-invasion in A.D. 623-628, which threw the Persian state into total chaos from which it never recovered. Shortly afterward, the Muslim hordes invaded and Persia lost its independence until the 16th century when the Safavid dynasty came to power. Facade of Continuity The Shahs of Iran maintained the pretense of an unbroken continuity from the days of Cyrus, and the last one holding a huge pageant in 1971 to celebrate the 2500th anniversary of the Persian empire, but he wasn't fooling anyone familiar with the history of the region. While the Persian Empire seems to have eclipsed all others, Persia was a great power in 400 B.C. and controlled much of the Ionian coast. We also hear of Persia much later at the time of Hadrian and, by all accounts, Rome avoided prolonged conflict with this rival power.