The Medes, who were once on the periphery of civilization, were transformed in the 700s BCE into a regional superpower that had a significant impact on history, including potentially preventing the Persian Empire from becoming the dominant power in the ancient world.
This is a historical sprint of the ancient world between 615-612 BCE, which was like the last burst of rocket fuel before the ancient era gave way to Greek classics and other stuff. During this period, the Assyrian army was the largest standing military force, equivalent to five modern heavy American divisions or almost eight Soviet field divisions.