Extent of the first Persian Empire, theAchaemenid Empire.

Extent of the second Persian Empire, the Parthian Empire.

Extent of the third Persian Empire, theSasanian Empire in 621.

The maximum extent of the Afsharid Empire under Nader Shah.

The Persian Empire is any of a series ofimperial dynasties centered in Persia(modern–day Iran). The first of these was established by Cyrus the Great in 550 BC with the conquest of Media, Lydia and Babylonia. Several later dynasties "claimed to be heirs of the Achaemenids".^[1]

Persian dynastic history was interrupted by the Muslim conquest of Persia in 651 AD and later by the Mongol conquest of Khwarezmia.

The main religion of ancient Persia wasZoroastrianism, but after the seventh century, it was replaced by Islam.

In the modern era, a series of Islamic dynasties ruled Persia independently of the universal caliphate. Since 1979 Persia has been an Islamic republic.