That happened more than 1,400 years ago. To ensure the future smooth implementation of their Heavenly Dao Plan, Lieyang Civilization's Regent Pan Zhen personally led a legion of ten thousand men to Earth, intending to take control of the planet.
The so-called Heavenly Dao Plan was actually propaganda aimed at lower civilizations with relatively large populations, meant to expand Lieyang's influence throughout the Known Universe, much like the angels spread justice across the Known Universe.
There were two reasons they chose Earth, located a hundred light-years from the Heavenly Dao Star System:
First, God of Death Karl had once left behind a Great Wormhole in the Chiwu Star System. That fellow had an extremely strong purpose behind everything he did. Though no one knew what it was for, Lieyang had to keep an eye on it.
Earth was the only planet in the Chiwu Star System with intelligent life at the time, so Lieyang set its sights on it.
Second, this was the main reason Lieyang went from initially considering Earth to deciding to take control of it.
After the Deno Star System was destroyed, Du Kao went to Earth under the guidance of Time God Kiran, bringing with him the remnants of Deno Civilization. As an old godly civilization, Lieyang naturally had no interest in what little advanced technology Deno had left. However, the powerful genes Du Kao brought to Earth were impossible to ignore.
For example, the Noxian God of War, who had once split Lieyang in half with a single axe strike; and the God River Power, an engineering project once jointly developed by angels and the God River civilization—later renamed Galaxy Power.
Du Kao alone had those two monstrously powerful God-Making Projects under his "control." Given his past behavior, who could guarantee he would not do