Terra nullius is a Latin expression meaning "nobody's land". It was a principle sometimes used in international law to justify claims that territory may be acquired by a state's occupation of it.

What did terra nullius mean?

Terra nullius means "nobody's land". This doctrine has existed in the law of nations throughout the development of Western democracy. The fact that it is a Latin phrase gives us the clue that it is derived from Roman law – the concept that ownership by seizure of a thing no one owns is legitimate.

Why was Australia declared terra nullius?

Possession of Australia was declared on the basis of unilateral possession. The land was defined as terra nullius, or wasteland, because Cook and Banks considered there were few 'natives' along the coast. They apparently deduced that there would be fewer or none inland.