Achaemenēs (Haxāmaniš "Friendly in Nature", Hellenised as Ἀχαιμένης, English /ə'kɛməni:z/) was the eponymous ancestor of the Achaemenid Dynasty, which ruled Persia between 705 BC and 675 BC. As an eponymous ancestor of the clan, Achaemenes is very often held to be legendary. Achaemenes is generally known as the leader of one of the clans of one of the ten to twelve Persian tribes, the Pasargadae. Persian royal inscriptions such as the Behistun Inscription place him five generations before Darius the Great; therefore, if Achaemenes was real, he would have lived around 700 BC. Although inscriptions label him as a "king, the leaders of the Persians at that time were in reality tribal chieftains. Which may mean that he was the first official king of the Persians.
Due to the lack of historical sources on Achaemenes, there is no way to know anything about him for certain; there is even reason to doubt his existence. Darius the Great rose to the position of Shah (king) in 522 BC by killing Bardiya, son of the Persian conqueror Cyrus the Great. Darius was able to claim legitimacy by pointing to his descent from Achaemenes. Consequently, Darius had much to gain by pointing to an ancestor shared by Cyrus and himself. It is sometimes contended then that Achaemenes is an invention of Darius. And others mention the fact that Darius did not need to invent such a character, which he could have claimed his legitimacy from Teispes. But an inscription from Pasargadae mentions Cyrus calling himself as descended from Achaemenes.
In any case, the Persian royal dynasty from Darius onward revered Achaemenes and credited him as the founder of their dynasty. Very little, however, was remembered about his life or actions. Assuming he existed, Achaemenes was most likely a 7th century BC warrior-chieftain, or the probable first king, who led the Persians, or a tribe of Persians, as a vassal of the Median Empire. An Assyrian inscription from the time of King Sennacherib in 681 BC, mentions that the Assyrian king almost repelled a raid by the Parsua and Anzan, with the Medians on the city of Halulina, which mentions Achaemenes as one of the commanders.
Ancient Greek writers provide some legendary information about Achaemenes: they call his tribe the Pasargadae, and say that he was "raised by an eagle". Plato, when writing about the Persians, identified Achaemenes with Perses, ancestor of the Persians in Greek mythology. According to Plato, Achaemenes/Perses was the son of the Ethiopian queen Andromeda and the Greek hero Perseus, and a grandson of Zeus. Later writers believed that Achaemenes and Perses were different people, and that Perses was an ancestor of the king.
Persian and Greek sources state that Achaemenes was succeeded by his son Teispes, who would lead the Persians to conquer and settle in the Elamite city of Anshan in southern Iran. Teispes' great-grandson Cyrus conquered the Medes and established the Persian Empire. Teispes is referred to as a son of Achaemenes in the Old Persian texts at Behistun.