The Iranian peoples are a collection of ethnic groups defined by their usage of Iranian languages and discernible descent from ancient Iranian peoples. The Iranian peoples live chiefly in the Middle East, Central Asia, the Caucasus, and parts of South Asia, though speakers of Iranian languages were once found throughout Eurasia, from the Balkans to western China. The Iranian peoples have played an important role throughout history: the Achaemenid Persians established the world's first multi-national state, and the Scythian-Sarmatian nomads dominated the vast expanses of Russia and western Siberia for centuries with a group of Sarmatian warrior women possibly being the inspiration for the Greek legend of the Amazons. In addition, the various religions of the Iranian peoples, including Zoroastrianism and Manichaeism, were important early philosophical influences on Judeo-Christianity. Early Iranian tribes were the precursors to many diverse modern peoples, including the Persians, the Kurds, the Pashtuns, and many other, smaller groups.