Zoroastrianism is one of the world's oldest religions, "combining a cosmogonic dualism and eschatological monotheism in a manner unique... among the major religions of the world." It was founded by the Prophet Zoroaster (or Zarathustra) in ancient Iran approximately 3500 years ago. It was the official religion of Persia (Iran) from 600 BCE to 650 CE. Originating with Iranian tribes living in Central Asia in the second millennium BCE, Zoroastrianism was the official religion of the Iranian empires until Islam superseded it in the seventh century AD. Ascribed to the teachings of the prophet Zoroaster, its Supreme Being is Ahura Mazda. Leading characteristics, such as messianism, the Golden Rule, heaven and hell, and free will influenced other religious systems, including Second Temple Judaism, Gnosticism, Christianity, and Islam. For a thousand years, forms of Zoroastrianism (including a Mithraic Median prototype and Zurvanist Sassanid successor) was one of the world's most important faith traditions, serving as the state religion of the pre-Islamic Iranian empires from around 600 BCE to 650 CE. Zoroastrianism was suppressed from the 7th century onwards following the Muslim conquest of Persia. Recent estimates place the current number of Zoroastrians at around 2.6 million, with most living in India and Iran. Besides the Zoroastrian diaspora, older Mithraic faith like Yazdanism is still practised amongst the Kurds.