Why did the Roman Empire eventually draw against the two Iranian empires but lose against the Germanic tribes? Why did the Germanic tribes manage to conquer permanently parts of the Roman Empire while the Iranian Empires did not? - TL Winslow

https://yourdailydoseofhistory.quora.com/Why-did-the-Roman-Empire-eventually-draw-against-the-two-Iranian-empires-but-lose-against-the-Germanic-tribes-Why-did-t-1