"Thus saith the LORD to his anointed, to Cyrus, whose right hand I have holden, to subdue nations before him; and I will loose the loins of kings, to open before him the two leaved gates; and the gates shall not be shut; I will go before thee, and make the crooked places straight: I will break in pieces the gates of brass, and cut in sunder the bars of iron: And I will give thee the treasures of darkness, and hidden riches of secret places, that thou mayest know that I, the LORD, which call thee by thy name, am the God of Israel. For Jacob my servant's sake, and Israel mine elect, I have even called thee by thy name: I have surnamed thee, though thou hast not known me." (Isaiah 45:1-4)
The Lord names Cyrus His anointed or messiah. As an instrument in God's hand, Cyrus would liberate the Jewish captives of Babylon in 539 BC.
While God was preparing the Babylonians to bring punishment upon Judah, He was also preparing Judah's deliverer. As the grandson of the Median king Astyages, Cyrus came to the throne in 559 BC. His father, Cambyses I, married the daughter of Astyages. At the time, the country of Media ruled over the Persians, and Cambyses I was employed as a vassal king. Upon the death of his father, Cyrus took over the position as vassal king under Astyages; however, rebellion soon broke out, and Astyages sent his commander to attack Cyrus and his troops. Rather than carry out his orders, Astyages' general defected with much of his army and encouraged Cyrus to attack his own grandfather. This he did, marching against the capital of Ecbatana and seizing the Median throne in 550 BC.
Now king of the entire empire of the Medes and Persians which resided in the northern part of present day Iran, Cyrus soon commenced expanding his kingdom. God had promised to hold Cyrus' hand and to subdue nations before him. The Lord carried out this promise as Cyrus marched west and attacked the Lydians in Asia Minor (Anatolia). Croesus, the leader of the Lydians, was defeated and the Lydian empire along with its subjected provinces was added to the Persian kingdom.
Cyrus' attention was then turned upon the lowlands of Babylon. By this time, the Babylonians had become estranged from their king Nabonidus who spent more time away from Babylon than he did ruling it. Nabonidus' son, Belshazzar, presided over Babylon under his father who had offended many of Babylon's citizens including the priesthood by his disregard for major religious festivals. In 539 BC, the Babylonian army was defeated at Opis which resided along the Tigris River north of Babylon. The remaining troops fled to the highly fortified Babylon where Belshazzar carelessly resided according to the testimony of Daniel. While drinking himself drunk and blaspheming the God of Israel, Belshazzar was unaware that the Persians were redirecting the waters of the Euphrates River which ran through the city. By diverting some of the river into a nearby canal, the Persians were able to penetrate the city successfully through the main water gate. Daniel records, "In that night was Belshazzar the king of the Chaldeans slain. And Darius the Median took the kingdom, being about threescore and two years old (Daniel 5:30-31)." Darius the Mede ruled as king of Babylon under the hand of Cyrus to whom God gave the hidden riches of Babylon.
In all of this, the Almighty profited Cyrus' path; yet, the text plainly declares, "...Thou hast not known me."