Hatra is an excellent example of the fortified cities laid out on the circular plan of the eastern city, such as Ctesiphon, Firouzabad or Zingirli. The perfect condition of the double wall in an untouched environment sets it aside as an outstanding example of a series which covers the Parthian, Sassanid, and early Islamic civilization. It provides, moreover, exceptional testimony to an entire facet of Assyro-Babylonian civilization subjected to the influence of Greeks, Parthians, Romans and Arabs.
Although there are few texts referring to the obscure beginnings of Hatra, it seems that a smallish Assyrian settlement grew up in the 3rd century BC becoming a fortress and a trading centre. Founded by nomadic horsemen from a Khorasan tribe, the Parthian empire of the Arsacid dynasty (247 BC-AD 226) claimed to be the successor of the Achaemenid Empire of Cyrus. In the 2nd century BC, it flourished as a major staging-post on the famous oriental silk road to become another of the great Arab cities as Palmyra in Syria, Petra in Jordan, and Baalbek in Lebanon. This Eastern monarchy was a source of concern for the Romans who sought unsuccessfully to destroy it. Read more about this site on the UNESCO World Heritage website.