Megiddo is the royal box in one of the great theatres of history. From time immemorial armies have surged from the surrounding valleys to play their parts on the flat stage of the Jezreel valley. Not surprisingly, Armageddon (=HarMegedon =Mountain of Megiddo) has become the symbol for the battle to end all wars (Rev.16:16).
Its position at the head of the most important pass through the Carmel range gave Megiddo control of the Way of the Sea, the ancient trade route between Egypt and the east. Traders from all over the known world passed its gates, as did invading armies. It was a strongly fortified city before 3000 BC, but its name first appears on the walls of the Temple of Karnak where Thutmose III had carved a detailed record (the earliest known) of the victorious battle he fought at Megiddo in 1468 BC. It remained a vassal city-state of Egypt for over a hundred years; six letters from its king, Biridiya, were found in the archives of the Egyptian foreign ministry at Amarna, one howling for aid against Shechem. The quality of the architecture and hoards of ivory, gold, and jewelry bear witness to the great prosperity of the city.
Too strong to be taken by the invading Israelites (Judg. 1:27), it probably fell to David. Solomon (965-928 BC) surrounded the summit with a casemate wall and filled the surface with public buildings, as befitted one of the most important cities of his realm. Destroyed in pharaoh Shishak’s campaign in 923 BC, it was rebuilt even more magnificently by Omri or Ahab in the mid- C9 BC. Megiddo fell in 733 BC to the Assyrians who made it the capital of the province of Galilee. They gave it spacious private dwellings and a new grid street system.
In the C7 BC Megiddo suddenly and inexplicably loses all importance, it became an open settlement with a small fortress. By the C4 BC it was uninhabited, and was never resettled.
Source: The Holy Land by Jerome Murphy- O’Connor