The Sassanid Persian Period

The Sassanid Persian Period covers the rule of the Sassanid dynasty over the Persian Empire from 224 to 651 CE, founded by Ardashir I after he overthrew the preceding Parthian Empire, and generally regarded as the last great pre-Islamic Persian empire and a major rival power to Rome and then Byzantium throughout its existence. The Sassanids revived and centralized Persian imperial administration, established Zoroastrianism as a state religion with an organized clergy, and fought a long series of wars against Rome and the Byzantine Empire over control of Mesopotamia, Armenia and the Caucasus, including a prolonged and mutually exhausting conflict in the early seventh century under Khosrow II. That final war against Byzantium left both empires severely weakened just before the rise of Islam, and the Sassanid Empire was conquered by Arab Muslim armies between 633 and 651 CE, an event that ended nearly four and a half centuries of Sassanid rule.