The religion Zoroastrianism is believed by some to have originated in what is now Afghanistan between 1800 and 800 BCE, as its founder Zoroaster is thought to have lived and died in Balkh while the region at the time was referred to as Ariana. Ancient Eastern Iranian languages may have been spoken in the region around the time of the rise of Zoroastrianism. By the middle of the 6th century BCE, the Achaemenids overthrew the Medes and incorporated Arachosia, Aria, and Bactria within its eastern boundaries. An inscription on the tombstone of Darius I of Persia mentions the Kabul Valley in a list of the 29 countries that he had conquered.