It is said that law attaches great importance to mere possession even without ownership. Even a wrongful possession is protected.
For instance, an owner of property (say x) dispossess am occupant (say y) without y’s consent. X is liable to restore possession even though the occupant is unable to show any right to be in possession.
Thus, even a trespasser, if allowed to be in occupation by negligence, cannot be disturbed even by the true owner. This is so as the trespasser is treated as a person having settled position.
A wrong possession of property for a period of 12 years is known as adverse position. It destroys the right of the owner vis-a-vis the occupant. A person acquires title to anything which is previously unowned. It is known as res-nullius.