Final answer:
Three German tribes that attacked Rome's western frontiers were the Goths, Vandals, and Visigoths, while the Persian rulers who attacked from the East were the Parthians and Sassanids.
Step-by-step explanation:
Three German tribes that attacked Rome's western frontiers were the Goths, the Vandals, and the Visigoths. These tribes, along with other Germanic tribes, invaded the Roman Empire during the fifth century CE, destabilizing the empire and eventually leading to its downfall. From the east, the Persian rulers who attacked Rome were the Parthians and later the Sassanids. Rome and Persia engaged in periodic raiding and full-scale warfare, but neither side was able to conclusively defeat the other.