Ardashir I Captures Ctesiphon, Founding the Sassanian Empire
On June 29, 226, Ardashir I seized the great city of Ctesiphon from the Parthians, a victory that confirmed him as the founder of the Sassanian Empire in Persia. According to later chronicles, the fall of the city marked the end of Parthian dominance in the region. From Ctesiphon, Ardashir organized a centralized state that became a powerful rival to Rome and then Byzantium. The Sassanian dynasty that grew from this moment shaped religion, culture, and warfare across the Near East for more than four centuries.