Parthia (or Parthian Empire and Arsacid Empire) was once a major power in ancient Iran and Iraq. The name of the empire was given by Arsaces I of Parthia who was the leader of the Parni tribe, founded the empire in the mid-3rd century BC when the region was conquered in 171-138 BC. Parthia was expanded from those times and Media as well as Mesopotamia was seized from the Seleucid Empire. At the height of Parthia's empire, it stretched from the north of the Euphrates to what is known today as central-eastern Turkey and then all the way to eastern Iran. The empire was located on the Silk Road trade route between the Mediterranean Basin and the Han Empire. This trade route was the world's greatest center of trade and commerce.