In astrology, the Royal Stars of Persia are Aldebaran, Regulus, Antares and Fomalhaut. They were regarded as the guardians of the sky in approximately 3000 BCE during the time of the Ancient Persians in the area of modern-day Iran. The Persians believed that the sky was divided into four districts with each district being guarded by one of the four Royal Stars. The stars were believed to hold both good and evil power and the Persians looked upon them for guidance in scientific calculations of the sky, such as the calendar and lunar/solar cycles, and for predictions about the future.