What does Daniel 2:37 mean?

Nebuchadnezzar (Daniel 1:1–2; 2:1) was a powerful king, with a kingdom unrivaled by any other. His empire towered over others the way a king controls his own subjects. Other prophets of that era, such as Ezekiel, use the same "king of kings" phrase in reference to Nebuchadnezzar (Ezekiel 26:7). Through prophets like Jeremiah, (Jeremiah 27:3–7), God warned nations such as Edom, Moab, Ammon, Tyre, and Sidon, that Nebuchadnezzar would subdue them and their nations would serve him. Daniel credits the Lord God's provision for Nebuchadnezzar's status as the world's greatest king. All of this would come about because of God's plan and according to His purpose.

Daniel's description, "the God of heaven," was well known by the Jews. The temple lay in ruins in Daniel's day, and God's presence and authority moved from the ark of the covenant to the heavens. Interestingly, decades later when the Lord moved Cyrus the king of Persia to release Jewish captives to rebuild the temple in Jerusalem, the king referred to the Lord as "the God of heaven" (Ezra 1:2).