Persians
Persians may refer to speakers of the Persian language, an Indo-European language. They are the predominant ethnic group of Iran, historically referred to as Persia.
The Persian language is also spoken elsewhere, notably in areas formerly ruled by the Persian Empires.
The name Persia derives from Parsa, the name of an Indo-European nomadic people who migrated into what is now southern Iran about 1000 BC (then called Persis), and who later created the Achaemenid Empire, also known as the First Persian Empire. As the Parsa expanded their sphere of political influence, the entire Iranian plateau became known as Persia, with its various peoples designated collectively as Persians.
The Iranian plateau has been conquered several times from various directions by various groups and there may also have been mixing with groups such as slaves. Thus, the modern Persians are not synonymous with the Indo-European Parsa.