From Wikipedia

Engineering An Empire

Persia

The Achaemenid Empire
(ca. 550–330 BC),
also known as the Persian Empire,
was the successor state of the Median Empire, ruling over significant portions of what would become Greater Iran. The Persian and the Median Empire taken together are also known as the Medo-Persian Empire, which encompassed the combined territories of several earlier empires.

At the height of its power, the empire encompassed approximately 8 million km². The empire was forged by Cyrus the Great, and spanned three continents: Asia, Africa and Europe. At its greatest extent, the empire included the territories of Iran, Afghanistan and northwest of India, parts of Central Asia, Asia Minor, Thrace and Macedonia, much of the Black Sea coastal regions, Iraq, northern Saudi Arabia, Jordan, Palestine, Israel, Lebanon, Syria, and all significant population centers of ancient Egypt as far west as Libya. It is noted in western history as the foe of the Greek city states during the Greco-Persian Wars, for emancipation of slaves including the Jews from their Babylonian captivity, and for instituting the usage of official languages throughout its territories. The Achaemenid Persian empire was invaded by Alexander III of Macedon, after which it collapsed and disintegrated in 330 BC into what later became the Ptolemaic Kingdom and Seleucid Empire, in addition to other minor territories which gained independence after its collapse.

In universal history the role of the Persian empire founded by Cyrus the Great lies in their very successful model for centralized administration and a government working to the advantage and profit of all.