This prophetic dream was a revelation of the kingdoms of the world from Babylon through to the Second Coming of The Lord Jesus Christ.
A. Babylon was the head of gold
Daniel interpreted the dream and declared Nebuchadnezzar (Babylon) to be the head of God (Dan.3:38).
B. Media-Persia was the breasts and arms
Daniel told Nebuchadnezzar that there "shall arise another kingdom inferior to thee" (Dan.2:32,39). This kingdom was Media-Persia and is not named by Daniel in his interpretation but Gabriel does in Dan.8:20-21. Also History does tell us the next kingdom after Babylon was Media-Persia.
C. Greece was the belly and thighs
Daniel told Nebuchadnezzar that there would be a third kingdom, (the belly and thighs of brass that shall "bear rule over all the earth" (Dan.2:39). History records this to be the kingdom of Greece, under the leadership of Alexander the great and Gabriel also acknowledges Greece as the next kingdom (Dan. 8:20-21).
D. There was yet a fourth kingdom to rise
(Rome -The two legs of iron) The "fourth kingdom shall be strong as iron: forasmuch as iron breaketh in pieces and subdueth all things...shall it break in pieces and bruise" (Dan.2:40). History records this "fourth kingdom shall be strong as iron" to be Rome which was divided into two, east and west.
E. The two legs of iron (Rome) reach until the "last days."
The reason for this conclusion is because the stone cut without hands (Dan.2:44-45) is when the "kingdoms of this world...become the kingdoms of our Lord, and of His Christ; and He shall reign for ever and ever"(Rev.11:15).
F. The two iron legs (Rome) had ten toes In the last days preceding the return of Christ, Rome will divided up into ten divisions (Dan.2:40-44) and because "they shall mingle themselves with the seed of men...they shall not cleave one to another" (Dan. 2:43).