Complex sentence: In Hellenist religious tradition, gods were served by priests and goddesses by priestesses but up to the Imperial era, Roma's priesthood was male-perhaps to acknowledge the essential virility of Rome's military power.
Split into simpler sentences: In Hellenist religious tradition, gods were served by priests and goddesses by priestesses. Up to the Imperial era, Roma's priesthood was male-perhaps to acknowledge the essential virility of Rome's military power.