What marked the limits of roman expansion to the east?

The roman expansion in the east was limited by the Parthian Empire. Parthian empire was able to stop Roman expansion to the east when they reached their empire. this was done through war but Parthians had a strong political core as well as a military advantage which made them win.

Roman expansion to the east reached its limits when it encountered the Parthian Empire. The Parthian Empire was a prosperous empire that had flourished to the East. When Roman expansion reached Mesopotamia, the Parthian were able to stop Romans through military resistance