The Great Ultra War was a conflict that pitted the army of Alien Emperor against the Ultras over the Land of Light. Although Emperor temporarily managed to takeover the planet, the Ultras fought back and defeated him.
Although the events are unclear, it is known that Emperor took control of the Land of Light after leading the most successful attack on the Ultras, something that various Ultramen foes had trouble doing. However, his reign was short-lived as the beings of light fought back, initiating the battle between light and darkness.
Related Post : Source : ultra-wikia
