Daniel 7:1 says, "In the first year of Belshazzar king of Babylon Daniel saw a dream and visions of his head upon his bed. Then he wrote down the dream; he related the sum of the matters." This indicates that the year of the vision in chapter seven was the first year of Belshazzar king of Babylon, about 555 B.C. The captivity began in 606 B.C., and the return of the children of Israel from captivity took place in 536 B.C., nineteen years after Daniel saw this vision.
Daniel 7:2-8 describes the four beasts which came out of the Mediterranean Sea. The Mediterranean Sea was the center of the inhabited earth. God's economy in His creation was to make the Mediterranean area the center of culture up to the time of Columbus. Human culture has become a great sea full of winds and storms.
The four winds of heaven stirred up the great sea, and four beasts came up from the sea (vv. 2-3). This does not mean that heaven is the source of these beasts but that heaven arranged the situation that produced the four beasts. The four winds signify moves of heaven from four directions; the stirring up of the great sea signifies the stirring up of the political situation around the Mediterranean Sea; and the four beasts which came up from the sea signify four great, fierce, cruel, and inhuman kings with their empires (v. 17).
In chapter two, in Nebuchadnezzar's dream human government on the earth was signified by a great human image full of glory and splendor. In chapter seven it was unveiled to God's prophet, Daniel, that the heads of human government on the earth, and the governments themselves, were signified by wild beasts.