The Achaemenid Persian Empire was something new in history: a hyper-power without serious rival, a world empire on an unprecedented scale.

At its territorial height under Darius I and Xerxes (early fifth century bce), the Achaemenid Empire ruled territory stretching from the western edge of the Himalayas to Libya and the Sudan and from the Indus River Valley to the Danube.

The Medes, from whom the Persians purportedly developed much of their own organizational framework, are generally considered the Persians' imperial predecessors, but the traditional representation of the “Median Empire” has be­come difficult to maintain. There were two principal features that underlay the suc­cess of Achaemenid Persian rule: an intricate administration that managed massive resources over vast territories in conjunction with a sustained, compelling ideology centered upon the king. The Achaemenids were, of course, indebted to numerous ideological and organizational elements of their predecessors—especially the Elamites, Assyrians, and Babylonians—in the ancient Near East, but they were mas­ters at adopting and adapting previous structures.

After the fall of Nineveh (612 bce) and the collapse of the Assyrian Empire, three major powers dominated the ancient Middle East: the Babylonians (heirs to much of the Assyrian realm), the Lydians in Anatolia, and the Medes in northern Iran. By the end of Cyrus the Great's reign in 530, the Persians had conquered each of the three great powers and additional lands besides. Cyrus's son Cambyses added Egypt and parts of modern Libya and the Sudan to the empire, and Darius I added further territory in northeastern Africa, the Indus Valley, and parts of southeastern Europe. With some fluctuation—most notably the loss of Egypt for roughly 60 years in the fourth century—the empire's dominion remained stable for over 200 years, until the conquests of Alexander of Macedon in the late 330s. Despite Alexander's startling achievement in conquering this vast empire, the unification of west and east did not survive his death. This chapter will include a historical sketch of the Median and Achaemenid periods, along with overviews of the Achaemenid court, administration, ideology, and Alexander's conquest of the empire.

Matthew W. Waters, The Achaemenid Persian Empire In: The Oxford World History of Empire. Edited by: Peter Fibiger Bang, C.A. Bayly, Walter Scheidel, Oxford University Press (2021). © Oxford University Press. DOI: 10.1093/oso/9780197532768.003.0004.