The Sasanian Empire was a major Persian state that existed from 224 to 651 CE. It succeeded the Parthian Empire and is known for its significant cultural, political, and economic achievements. The Sasanian period is marked by advancements in art, architecture, and science, as well as the establishment of Zoroastrianism as the state religion. The empire expanded its territory, reaching its height under rulers like Khosrow I. The Sasanian Empire was a key player in the ancient world, often in conflict with the Roman Empire. Its fall to the Arab conquests led to the spread of Islam and significant changes in the region's cultural landscape.