WORLD HISTORY

Detailed explanation-1: -For almost three decades, Rome and Persia were locked in a conflict that had begun as an attempt by Khusro II to oust the murderer of his benefactor, Maurice, but then evolved into a struggle to control all of the eastern provinces.

Detailed explanation-2: -Wave after wave of Germanic barbarian tribes swept through the Roman Empire. Groups such as the Visigoths, Vandals, Angles, Saxons, Franks, Ostrogoths, and Lombards took turns ravaging the Empire, eventually carving out areas in which to settle down.

Detailed explanation-3: -Romans withdrew from the homeland territory of Persia with the 363 AD defeat of Jovian, and only Byzantine emperor Heraclius was able to return and conquer Gazaca (the capital of Atropatene) during the Byzantine–Sasanian War of 602–628, just a few years before the Arab conquest of Sassanian Persia.

Detailed explanation-4: -They just couldn’t pull it off-Persia was too far, and the Persians were too strong. While the Roman Republic and Empire were arguably stronger than either Parthian or Sassanid Persia, the Romans weren’t able to effectively project that power for a sustained campaign of conquest into Persia.