What does the battle of Armegeddon conjure up in your imagination? What about the battle of Gettysburg? Revelation 16:16 details the most famous of the battles fought at Megiddo. Just as multiple battles were fought at Manassas (or Bull Run) during the American Civil War, so multiple battles were fought during Biblical times at Megiddo. It was the site of two major Israeli victories; of Barak over the Canaanites, and of Gideon over the Midianites. It was also the location of two significant disasters; the death and defeat of King Saul and King Josiah, and their armies. Napoleon Bonaparte himself testified that the hills and the plains of Megiddo were geographically a choice location to have a major engagement.
Josephus records the fulfillment of Revelation 16:16 and last battle of Armegeddon in his book The War of the Jews. Vespasian and Titus and three legions over-ran Israel during the 3 1/2 year Roman-Judeo War of AD 67-70. Towards the end, the Romans trapped the Zealots and many others inside Jerusalem, sieged the city, and destroyed it. Thus fulfilling Matthew 22:7 & 23:35. The Christians, however, heeded Christ's warning in Matthew 24:16, and fled into the Judean mountains to a city called Pella. The Church Historian Eusebius records these facts. In addition to the three Roman Legions (the fifth, tenth, and fifteenth), auxileraries and cavalry from the entire Roman World (oikumene) joined in the Roman-Judeo campaign. Some Christians believe that Revelation 16:16 is yet to be fulfilled, but both recorded history and the Holy Scriptures testify otherwise. The battle of Armegeddon does not involve jets, machine guns, nuclear weapons, poison gas, or rpg's; anymore than the battle in Ezekiel Chapters 38 and 39 did (see Esther 9:16). Revelation 16:16 lists one of the five major Biblical battles fought at the plains / hills of Megiddo.
In Luke 21:20-22 Jesus said, "But when you see Jerusalem surrounded by armies, then know that her desolation is at hand. Then let those who are in Judea flee to the mountains, and let not those who are in the country enter the city; because these are the Days of Vengeance, in order that all things which are written may be fulfilled."