Sassanid

The Sassanid Empire, or Sassanian Empire, was the last great Iranian empire before the rise of Islam, lasting from 224 to 651 CE. It succeeded the Parthian Empire after Ardashir I defeated Artabanus III and established his capital at Ctesiphon. At its height the empire stretched from the eastern frontiers of the Roman world to the Arabian Peninsula and Egypt, and from the Caucasus to the Indian subcontinent.

The Sassanids established Zoroastrianism as the state religion, integrating it with royal ideology and law. They fostered a centralized bureaucracy and built a sophisticated urban and religious architecture, supported by Persian culture, and promoted the Persian language (Middle Persian) and Pahlavi script. The empire engaged in frequent military conflicts with the Byzantine Empire, with major campaigns led by rulers such as Shapur I and Khosrow I. Trade along the Silk Road flourished, and the empire acted as a cultural bridge between the East and West, influencing art, architecture, and religious thought.

The Sassanid dynasty faced internal strife, economic pressures, and continuous warfare with Byzantium. After prolonged conflict and expanding Arab Muslim forces, the last Sassanid ruler Yazdegerd III was toppled in 651, marking the end of the empire. The Sassanids left a lasting legacy in Iranian culture, administration, and religious thought and are regarded as a formative influence on later Persian-speaking empires, including the Islamic caliphates, and on the development of Persian language and literature.