The modern (actually, medieval) Roman Empire that we have been dealing with since Rev 13 is also in three parts: the beast of the sea, the land, and the image of the beast. The beast of the sea, having seven heads and ten horns, is the representation of the kingdoms of this world, which are all patterned after Babel in their philosophy and operation. … So the kingdoms of this world are represented by Rome, the terrible fourth beast of Daniel’s vision.
The second third is the beast from the land, which we saw the Roman papacy fulfilled, and the third of the thirds is the image of the beast whose deadly wound was healed, which is fulfilled in the Holy Roman Empire. (pp. 195-196).
“The beast is the Roman power in three forms, Imperial, Papal, and the Holy Roman Empire. The beast with seven heads is the secular power of the Roman Empire; the lamb-like beast who looks like Jesus but talks like the devil is the Papacy; the image to the beast is the Holy Roman Empire.”
– Fred Miller, Revelation: A Panorama of the Gospel Age, Ch. 9, “The Seven Last Plagues: The Decline and Fall of the Papacy.”