No-one knows exactly how Humans came to Corellia. It is obvious that Humans originated from both planets simultaneously, but recent discoveries have shed light on the theories that the Humans that came from Corellia were actually descended from Humans who came to prehistoric Corellia in a time machine and were stranded there, being reduced to a more primitive lifestyle. This would explain why the Humans of Corellia seemed to advance a lot faster than the Humans of Earth.
Corellia is a prosperous planet with a bustling trade, and it is one of the League's major footholds of influence in the Force Galaxy. It joined the Rebel Alliance during the Galactic Civil War and is the home planet of one of the War's greatest heroes, Han Solo.
Corellia was also the site of the main bulk of the Sith-Covenant War.