Vedic astrology originally comes to us from the Rig Veda, the oldest of the four Vedas, the spiritual Bible of ancient India. The Vedas were an oral tradition passed down from family to family, generation to generation. These works contain the spiritual teachings of Hinduism. Much later in their history the Vedas were put in a written form, and so it is with Jyotisha as well. We also find astrological references abound in the great oral Epics of India, the Mahabharata and the Ramayana, particularly in the most famous portion of the Mahabharata, the Bhagavad-Gita. Such ancient works as the Vedanta Jyotish and the Surya Siddhanta shed further light on both the astronomy and astrology of ancient India.
Later in history, about the 5th century AD, many of the previous oral astrological teachings were put into written form. Many of India's most well-known Astrologers-Sages lived during this time. Such personages as Parasara, Vaharamihira, Kalyana Varma and Mantreswar and their masterpieces on Vedic Astrology.