The Sasanian Empire (/səˈsɑːniən/ or /səˈseɪniən/), also known as Sassanian, Sasanid, Sassanid or Neo-Persian Empire), known to its inhabitants as Ērānshahr in Middle Persian, was the last imperial dynasty in Persia (Iran) before the rise of Islam, ruled by and named after the Sasanian dynasty from 224 to 651 AD. The Sasanian Empire, which succeeded the Parthian Empire, was recognized as one of the leading world powers alongside its neighboring arch-rival the Roman-Byzantine Empire, for a period of more than 400 years.
The Sasanian Empire was founded by Ardashir I, after the fall of the Parthian Empire and the defeat of the last Arsacid king, Artabanus V. At its greatest extent, the Sasanian Empire encompassed all of today's Iran, Iraq, Eastern Arabia (Bahrain, Kuwait, Oman, Qatif, Qatar, UAE), the Levant (Syria, Palestine, Lebanon, Israel, Jordan), Armenia, the Caucasus (Georgia, Azerbaijan, Dagestan, South Ossetia, Abkhazia), Egypt, large parts of Turkey, much of Central Asia (Afghanistan, Turkmenistan, Uzbekistan, Tajikistan), Yemen and Pakistan. According to a legend, the vexilloid of the Sasanian Empire was the Derafsh Kaviani.