Parry & Grant Encyclopaedic Dictionary of International Law said:
terra nullius ‘The expression “ terra nullius ” was a legal term of art employed in connection
with “occupation” as one of the accepted legal methods of acquiring sovereignty over a territory. “Occupation” being legally an original means of peacefully acquiring sovereignty over territory otherwise than by cession or succession, it was a cardinal condition of a valid “occupation” that the territory should be terra nullius— a territory belonging to no-one—at the time of the act alleged to constitute the “occupation” . . .’: Western Sahara Case 1975 I.C.J. Rep. 6 at 39. Cf . Eastern Greenland, Legal Status of, Case ( 1933 ) P.C.I.J., Ser. A/B, No. 53 at 44 and 63. In the words of 1 Oppenheim 687 , ‘The only territory which can be the object of occupation is that which does not already belong to another state, whether it is uninhabited, or inhabited by persons whose community is not considered to be a state; for individuals may live on as territory without forming themselves into a state proper exercising sovereignty over such territory’. See also Clipperton Island Case ( 1931 ) 2 R.I.A.A. 1105 ; Island of Palmas Case ( 1928 ) 2 R.I.A.A. 829 ; Minquiers and Ecrehos Case 1953 I.C.J. Rep. 47 ; Rann of Kutch Case ( 1968 ) 17 R.I.A.A. 1 ; Western Sahara Case 1975 I.C.J. Rep. 12 . And see Crawford, The Creation of States in International Law (2nd ed.), 265–268. The process whereby territory already subject to the sovereignty of another State may be acquired—and by very much the same method as for occupation —is referred to as prescription ( see prescription, acquisitive ).
SOURCE: Page 596 • Parry & Grant Encyclopaedic Dictionary of International Law •