It seems as if the people who built Persepolis, and this they did even before the ancient Romans created their world empire, appeared out of nowhere. Presumably it was a tribe of herdsmen who settled in the south-west of present-day Iran in the 8th century B.C. This region was known as Parsa, or Persis as the Greeks called it. When, in 550 B.C., the Achaemenid Kyros ascended the throne, it took only a few years for the Persian Empire to be feared as a terrifying opponent.