Great question.
To my knowledge, in the case of Australia, the Aboriginals that lived here for thousands of years undisturbed, remains have been excavated that are 60,000 years old, did not have private property, but rather everything was shared
So it was British colonialists that arrived with guns, circa 250 years ago, and started settling from Sydney harbour, enforcing their imported legal and property system
So yes, the lands were taken by force, and populated
