Zoroaster (Greek Ζωροάστρης, Zōroastrēs) or Zarathustra (Avestan: Zaraθuštra), also referred to as Zartosht (Persian: زرتشت), was an ancient Iranian prophet and the founder of Zoroastrianism, a religion that was the national religion of the Sassanid Empire of Persia; it is predominantly practiced today by the Parsi community of India.
Zoroaster is generally accepted as an authentic historical figure, but the period in which he lived remains unclear. Many scholarly estimates place him circa 1200 B.C., making him a candidate to be the founder of the earliest religion based on revealed scripture, while others place him anywhere between the 18th and the 6th centuries B.C.
The teachings of Zoroaster are presented in the yasna, seventeen liturgical texts or "hymns," which is divided into groups called Gāthās. The basic precept of Zoroastrianism is the maxim "Humata, Hukhta, Huvarshta" Sanskrit sumata, sukta, suvartana) — “Good Thoughts, Good Words, Good Deeds.”