The Sasanian Empire (səˈsɑːniən,_səˈseɪniən), officially known as Eranshahr ("Land/Empire of the Iranians"), was the last Iranian empire before the early Muslim conquests of the 7th–8th centuries AD. Named after the House of Sasan, it endured for over four centuries, from 224 to 651 AD, making it the longest-lived Persian imperial dynasty. The Sasanian Empire succeeded the Parthian Empire, and re-established the Persians as a major power in late antiquity alongside its neighbouring arch-rival, the Roman Empire (after 395 the Byzantine Empire). The empired ended with the Arab conquest of Iran.
The empire was founded by Ardashir I, an Iranian ruler who rose to power as Parthia weakened from internal strife and wars with the Romans. After defeating the last Parthian shahanshah, Artabanus IV, at the Battle of Hormozdgan in 224 AD, he established the Sasanian dynasty and set out to restore the legacy of the Achaemenid Empire by expanding Iran's dominions. At its greatest territorial extent, the Sasanian Empire encompassed all of present-day Iran and Iraq, and stretched from the Levant to the Indian subcontinent and from South Arabia to the Caucasus and Central Asia.
The period of Sasanian rule was a high point for Iranian civilization, characterized by a complex and centralized government bureaucracy, and revitalized Zoroastrianism as a legitimizing and unifying force of their rule. They also built grand monuments, public works, and patronized cultural and educational institutions. The empire's cultural influence extended far beyond its territorial borders—including Western Europe, Africa, China, and India—and helped shape European and Asian medieval art. Following the Arab conquests, the influence of Sasanian art, architecture, music, literature and philosophy on Islamic culture ensured the spread of Iranian culture, knowledge and ideas throughout the Muslim world.