P actually possessed disputed land for over statutory time (1951-1968), however, both P and D were mistaken about true owner.
Does adverse possession require a specific intention to exclude true owner?
No, where acts are unequivocal, intention is presumed. Where acts are equivocal, specific intention is important.
Adverse possession is (Banning, "The State of the Law of the Limitations of Action):
-"Any possession inconsistent with the title of the lawful owner."
-"All possession without the direct authority of the owner may now be considered as adverse"
Intention is important when acts are equivocal, but when acts are clear, intention is presumed (Littledale v Liverpool).
-Enclosure is the "Strongest possible evidence of adverse possession" (Seddon v Smith)
--P unequivocally exercised control over the disputed land and even enclosed it.