(559–330 BC) Early Persian dynasty.
It derives its name from Achaemenes, who is thought to have lived in the early 7th century BC. From his son Teispes were descended two lines of kings. The older line included Cyrus I, Cambyses I, Cyrus II (the Great), and Cambyses II; the junior line began with Darius I and ended with the death of Darius III after his defeat by Alexander the Great (330 BC). Its greatest rulers were Cyrus II (r. 559–с 529 BC), who actually established the Persian empire and from whose reign it is dated; Darius I, who secured the borders from external threats; and Xerxes I , who completed many of Darius's public works. At its height, the Achaemenian Empire reached from Macedonia to northern India and from the Caucasus Mountains to the Persian Gulf. The ruins of one of its capitals, Persepolis , survive from its golden age.