The Battle of Earth was a series of invasions of Earth by several aliens, including the Mech and Terran Empires. The battle lasted for roughly fifteen wars and ended in an indecisive Mech/Terran victory. It led to a war between several races and the collapse of the Sentient Protection Alliance. It also indirectly led to the Great Galactic Extermination. About 70% of all humans on Earth were killed, though many were evacuated to other planets.