May be read separately or as a reference found in Zechariah 14:4:

The word  “Armageddon” comes from a Hebrew word Har-Magedone, which means “Mount  Megiddo” and has become synonymous with the future battle in which God will  intervene and destroy the armies of the Antichrist as predicted in biblical  prophecy (Revelation  16:16; 20:1-3, 7-10). There will be a multitude of people engaged in the  battle of Armageddon, as all the nations gather together to fight against  Christ.

The exact location of the valley of Armageddon is unclear  because there is no mountain called Meggido. However, since “Har” can also mean  hill, the most likely location is the hill country surrounding the plain of  Meggido, some sixty miles north of Jerusalem. More than two hundred battles have  been fought in that region. The plain of Megiddo and the nearby plain of  Esdraelon will be the focal point for the battle of Armadeggon, which will rage  the entire length of Israel as far south as the Edomite city of Bozrah (Isaiah 63:1). The valley of  Armageddon was famous for two great victories in Israel’s history: 1) Barak’s  victory over the Canaanites (Judges 4:15)  and 2) Gideon’s victory over the Midianites (Judges 7). Armageddon was also the  site for two great tragedies: 1) the death of Saul and his sons (1 Samuel 31:8) and 2) the  death of King Josiah (2 Kings  23:29-30; 2  Chronicles 35:22).

Because of this history, the valley of Armageddon  became a symbol of the final conflict between God and the forces of evil. The  word “Armageddon” only occurs in Revelation  16:16, “Then they gathered the kings together to the place that in Hebrew is  called Armageddon.” This speaks of the kings who are loyal to the Antichrist  gathering together for a final assault on Israel. At Armageddon “the cup filled  with the wine of the fury of [God’s] wrath” (Revelation  16:19) will be delivered, and the Antichrist and his followers will be  overthrown and defeated. “Armageddon” has become a general term that refers to  the end of the world, not exclusively to the battle that takes place in the  plain of Megiddo.

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