The battle described in Rev. Chap 13 - 20 is a spiritual and physical battle. It is portrayed in God's picture language of metaphors and symbols that help us visualize certain aspects of the battle. As symbols and metaphors are used throughout Revelation, then it is necessary to define or identify those symbols. We can do so because of their prior use in the OT. But we begin by defining the context of this chap in vs. 1 -2:
"And there came one of the seven angels which had the seven vials, and talked with me, saying unto me, Come hither; I will shew unto thee the judgment of the great whore that sitteth upon many waters:
2 With whom the kings of the earth have committed fornication, and the inhabitants of the earth have been made drunk with the wine of her fornication." (KJV)
This battle is then defined as the judgment God was to pour out from the 7 vials upon the great whore. We need to identify the whore. Then we need to recognize the waters she sat upon, and the inhabitants of the earth who were drunk with the sins of her fornication.
First, we need to understand the usage of the word "earth" in prophesy, as it limits the scope of the battle, or prophesy being given. Earth here is Strong's Gr. 1093 "γῆ" or "ge" and means the earth, soil, land, region, country, inhabitants of a region. (Source: Biblehub)
The earth and the land in the prophesy is not just any earth or land, nor is it representing the whole of the earth. It is specifically directed to those that were under judgment, which were those who were in Jerusalem and Judea. Earth is used in prophetic language for the region of land, or the country the prophet was sent to warn. See how it is used in Deu 32:1,
"Give ear, O ye heavens, and I will speak; and hear, O earth, the words of my mouth." (KJV)
The prophet was calling two groups of people - the "heavens" and the "earth" of that country / land. Those of the "heavens" were the rulers or kings of the heavenly places of their kingdom. Those of the earth were the people the kings ruled over that inhabited the land. (Notes 1, 2)
We identify the prophet - Jesus- and then we identify to whom He was sent in order to know which land or country was receiving the warning.
Christ was sent to the lost sheep of the house of Israel (Matt. 10:6, Matt. 15:24). Not that their location was unknown, but that they had lost their spiritual way and wandered off the path of righteousness.
Therefore Christ being sent to the remnant of Israel - Judea and Jerusalem, then those inhabitants of the earth affected by this prophesy were Judea and Jerusalem.
Next we identify which was the whore that ruled over the "kings" or rulers of Jerusalem and Judea. And, we have that clue further down in vs. 5-6:
"5 And upon her forehead was a name written, Mystery, Babylon The Great, The Mother Of Harlots And Abominations Of The Earth.
6 And I saw the woman drunken with the blood of the saints, and with the blood of the martyrs of Jesus: and when I saw her, I wondered with great admiration." (KJV)
We have an earlier reference in Revelation to Babylon in Rev. 14:8 where "Babylon is fallen, is fallen, that great city,", which connects to an earlier reference in Rev. 11:8 is defined as
"And their dead bodies shall lie in the street of the great city, which spiritually is called Sodom and Egypt, where also our Lord was crucified." (KJV)
The city called Babylon, "that great city", also called Sodom and Egypt where our Lord was crucified was Jerusalem. Babylon was the whore, and Babylon was the great city, and as A = B = C, then Babylon was Jerusalem. It refers back to the same definition provided in the OT from Ezek 23:2-4, 17.
"2Son of man, there were two women, the daughters of one mother:
3 And they committed whoredoms in Egypt; they committed whoredoms in their youth: there were their breasts pressed, and there they bruised the teats of their virginity.
4 And the names of them were Aholah the elder, and Aholibah her sister: and they were mine, and they bare sons and daughters. Thus were their names; Samaria is Aholah, and Jerusalem Aholibah." (KJV)
"17 And the Babylonians came to her into the bed of love, and they defiled her with their whoredom, and she was polluted with them, and her mind was alienated from them." (KJV)
The whore of Babylon of Revelation was the same whore of Babylon of Ezekiel - Jerusalem. She fornicated with the kings / rulers of the lands through treaties with pagan nations, and walked away from her God (YHVH), her husband (Isa. 54:5; Jer. 3:14; 31-34). (3)
Jerusalem aligned herself with the Romans to kill and persecute Christ's saints, and was drunk with their blood. The battle was between the backsliding, whoring Jerusalem and her ally - the Romans - and Christ and His apostles and disciples. The war took place on the lands (earth) of Judea and ended with the destruction of that great city, that Babylon - Jerusalem.
"9 And the kings of the earth, who have committed fornication and lived deliciously with her, shall bewail her, and lament for her, when they shall see the smoke of her burning,
10 Standing afar off for the fear of her torment, saying, Alas, alas that great city Babylon, that mighty city! for in one hour is thy judgment come." (KJV)
The ten kings then would have to be ten rulers that ruled in Jerusalem, who would have power / alignment with the beast (Rome) for one hour - a limited time span. Many have attempted to number those 10 as the high priests or some of the Zealots who worked with Rome against Christ and His saints. It may not be possible to positively identify all of them, but they were those of Jerusalem, the earth of this battle and the earth of this prophesy.
The faithful elect that were fighting that battle with Christ were those spreading the gospel, the good news and who were walking in The Way. (4)
All of the metaphors and symbols God used in His prophesies were identified and defined in the OT. The OT is the code for the NT and for Revelation. See more at my blog ShreddingTheVeil on The Beast of Revelation here and all ten parts of The Signs of Revelation.
1) The Signs of Revelation - Part II: Codes & Symbols of Nature here
2) Revelation: The Four Corners of The Earth here
3) The Whore of Babylon here
4) The Gathering of The Elect here