The great city has always been the Holy City of Jerusalem, even though Babylon was a great city before it's destruction by the Persians in 539BC. Jesus was not crucified in Jerusalem, but outside the walls of Jerusalem on a hill in Golgotha that was also part of the Roman government in Jerusalem at the time of Christ and crucified Jesus according to their custom.
Rev 17 and 18 speaks of mystery Babylon as it is even a mystery to those today that have no understanding. In Rev 17 the great harlot rides the beast so the harlot can not be both the harlot and the beast. The seven heads are that of the Babylonian Empire, Medo/Persian Empire, Grecian Empire and Roman Empire. The ten horns represent the nations the Roman Empire scattered to when the deadly wound was put upon them as even today these nations are controlled by the Roman Empire, Daniel 7:23-25; Rev 13, 17, that would love nothing less then to escape this ruling power.
These ten nations were the Anglo-Saxons (English), the Franks (French), Suevi (Portuguese), Visigoths (Spanish), Burgundians (Swiss), Alemanni (Germans), Lombards (Italians), Ostrogoths, Heruli, and the Vandals in northern Africa. The last three being Ostrogoths, Heruli, and the Vandals had already been destroyed by the Roman Empire before their deadly wound came in 1798.
In Rev 17, 18, 19 the great harlot (son of perdition) is described and then destroyed along with the beast being the existing Roman Empire. The earth bewails their destruction as they were made rich by the woman. In the NT the term woman is used as a symbol for a church. The woman mentioned in Rev 12 is the true Church of God as she is carried away into the wilderness and taken care of by God.
This woman in Rev 17 sitting on a scarlet beast is a spiritual harlot as she entered into adulterous alliances with the leaders an kings of every nation around the world including America. Rev 18 describes all these worldly leaders and kings fornicated with her and will bewail her destruction. In her was found the blood of the prophets and the saints and all that were slain on earth.
Rev 14:6 And I saw another angel fly in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people, 7 Saying with a loud voice, Fear God, and give glory to him; for the hour of his judgment is come: and worship him that made heaven, and earth, and the sea, and the fountains of waters. 8 And there followed another angel, saying, Babylon is fallen, is fallen, that great city, because she made all nations drink of the wine of the wrath of her fornication. 9 And the third angel followed them, saying with a loud voice, If any man worship the beast and his image, and receive his mark in his forehead, or in his hand, 10 The same shall drink of the wine of the wrath of God, which is poured out without mixture into the cup of his indignation; and he shall be tormented with fire and brimstone in the presence of the holy angels, and in the presence of the Lamb: 11 And the smoke of their torment ascendeth up for ever and ever: and they have no rest day nor night, who worship the beast and his image, and whosoever receiveth the mark of his name. 12 Here is the patience of the saints: here are they that keep the commandments of God, and the faith of Jesus.
