By the 7th century BC, the Persians had settled in the southwestern portion of the Iranian Plateau in the region of Persis, which came to be their heartland. From this region, Cyrus the Great advanced to defeat the Medes, Lydia, and the Neo-Babylonian Empire, establishing the Achaemenid Empire. Alexander the Great, an avid admirer of Cyrus the Great, conquered most of the empire by 330 BC. Upon Alexander's death, most of the empire's former territory came under the rule of the Ptolemaic Kingdom and Seleucid Empire, in addition to other minor territories which gained independence at that time. The Iranian elites of the central plateau reclaimed power by the second century BC under the Parthian Empire.
The Achaemenid Empire is noted in Western history as the antagonist of the Greek city-states during the Greco-Persian Wars and for the emancipation of the Jewish exiles in Babylon. The historical mark of the empire went far beyond its territorial and military influences and included cultural, social, technological and religious influences as well. Despite the lasting conflict between the two states, many Athenians adopted Achaemenid customs in their daily lives in a reciprocal cultural exchange, some being employed by or allied to the Persian kings. The impact of Cyrus's edict is mentioned in Judeo-Christian texts, and the empire was instrumental in the spread of Zoroastrianism as far east as China. The empire also set the tone for the politics, heritage and history of modern Iran.
The Persian nation contains a number of tribes as listed here. ... : the Pasargadae, Maraphii, and Maspii, upon which all the other tribes are dependent. Of these, the Pasargadae are the most distinguished; they contain the clan of the Achaemenids from which spring the Perseid kings. Other tribes are the Panthialaei, Derusiaei, Germanii, all of which are attached to the soil, the remainder -the Dai, Mardi, Dropici, Sagarti, being nomadic.
The Achaemenid Empire was created by nomadic Persians. The name "Persia" is a Greek and Latin pronunciation of the native word referring to the country of the people originating from Persis (Old Persian: Pārsa), their home territory located north of the Persian Gulf in southwestern Iran.