The son of Ar-Gimilzor of Numenor and his consort Inzilbeth. Inziladun was secretly raised by his mother in the ways of the Faithful, that party of the Numenorean people who remembered their years of friendship with the Elves and respect for the Valar. When Inziladun succeeded his father to the Sceptre, he attempted to return Numenor to those old ways, halting the oppression of the Faithful, and recommencing the tradition of the Three Prayers that had long been abandoned.
As a reforming King, Inziladun took the Sceptre in the name of Tar-Palantir, meaning "The Far-Sighted", but his younger brother Gimilkhad was of quite a different mind. The strife between them was such that The Tale of the Years describes Tar-Palantir's reign as "civil war". Inziladun's restoration of the old ways did not last long: after his death, his daughter Miriel was forced as wife by Gimilkhad's son Pharazon, who thus usurped the Kingship and began Numenor's final decline.