Persians
Etymology
The term Persian, meaning "from Persia", derives from Latin Persia, itself deriving from Greek Persís (Περσίς), a Hellenized form of Old Persian Pārsa (𐎱𐎠𐎼𐎿), which evolves into Fārs (فارس) in modern Persian. In the Bible, particularly in the books of Daniel, Esther, Ezra, and Nehemya, it is given as Pārās (פָּרָס).
Etymology
A Greek folk etymology connected the name to Perseus, a legendary character in Greek mythology. Herodotus recounts this story, devising a foreign son, Perses), from whom the Persians took the name. Apparently, the Persians themselves knew the story, as Xerxes I tried to use it to suborn the Argives during his invasion of Greece, but ultimately failed to do so.
History of usage
Although Persis (Persia proper) was only one of the provinces of ancient Iran, varieties of this term (e.g., Persia) were adopted through Greek sources and used as an exonym for all of the Persian Empire for many years. Thus, especially in the Western world, the names Persia and Persian came to refer to all of Iran and its subjects.