God had warned his people Israel that disobedience to the Mosaic Covenant might result in exile from the Promised Land if that disobedience was wide-spread and prolonged (cf. Lev. 26:14, 33; Deut. 28:36, 48, 63). This is really what happened. The Assyrians under Shalmaneser V took over the Northern Kingdom of Israel (2 Kings 17:1-6; cf. 15:29) and deported the people to Assyria (2 Kings 17:6) in 722 B.C. The Neo-Babylonian Empire replaced Assyria as the major political force in the ancient Near East in 605 B.C. Later that same year the Babylonian army under Nebuchadnezzar invaded the Southern Kingdom of Judah and took some of the Jews captive to Babylon (2 Kings 24:1-4). Two more invasions and deportations by Nebuchadnezzar followed in 597 and 586 B.C. (2 Kings 24:10-17; 25:1-7). However, God had also promised that if His people in exile repented and returned to Him He would restore them to the Promised Land (Lev. 26:40-45; Deut. 30:1-5).
Over a century before the exile began Isaiah not only prophesied that Israel would experience exile but that she would eventually return to the land. Isaiah revealed that the name of the king who would allow Israel to return would be Cyrus (Isa. 44:28; 45:1). Cyrus inherited the throne of Anshan, a small state near the Persian Gulf, in 559 B.C. Due to his great leadership ability he was able to unite the Persian people. He then attacked the neighboring Medes and took their capital city, Ecbatana, without a battle. The Median soldiers abandoned their king to side with Cyrus. He then welded these two great peoples into the Medo-Persian Empire. He next conquered Lydia and Anatolia (the western part of modern Turkey) in 547-546 B.C. The Babylonian Empire was then in a weakened condition. Cyrus invaded its capital, Babylon, by diverting the waters of the Euphrates River that ran through the city and marching under the city wall on the dry riverbed. This took place in 539 B.C. This victory enabled Cyrus to establish Medo-Persia as the major political power in the ancient Near East.16
"From east to west, it [the Persian Empire] was as wide as the continental United States."17
Cyrus adopted a policy toward conquered peoples within his empire that was opposite to that of his Assyrian and Babylonian predecessors. They had deported defeated people from their homelands to minimize the threat of revolution. Cyrus on the other hand decided to allow these people to return to their former homes believing that this would please them and would discourage them from rebelling.
"Cyrus was one of the truly enlightened rulers of ancient times. Instead of crushing national sentiment by brutality and deportation as the Assyrians had, it was his aim to allow subject peoples as far as possible to enjoy cultural autonomy within the framework of the empire. Though he and his successors kept firm control through a complex bureaucracy--most of the high officials of which were Persians or Medes--through their army, and through an efficient system of communications, their rule was not harsh. Rather, they preferred to respect the customs of their subjects, to protect and foster their established cults and, where they could, to entrust responsibility to native princes."18