Denethor
In J. R. R. Tolkien's fictional universe of Middle-earth, Denethor II is the twenty-sixth and last Ruling Steward of Gondor. He succeeded his father Ecthelion II at his death in T.A. 2984.
Spoiler warning: Plot or ending details follow.
Denethor is known to have secretly used a palantír to probe Sauron's strength. The effort aged him quickly, and the knowledge of Sauron's overwhelming force depressed him greatly. Sauron used the palantír to drive him mad with despair. He retained, however, an air of nobility and power.
The death of Boromir, his firstborn and favorite, together with the siege and apparent doom of his capital city, drove him over the edge into insanity. He ordered his men to burn him alive on a funeral pyre with the palantír in his hands. He also attempted to take the grievously injured and apparently dying Faramir with him, but was thwarted in that by the timely intervention of Peregrin Took.
Denethor committed suicide in 3019. The Office of Steward passed to his younger son, Faramir.
In Peter Jackson's movie trilogy, Denethor was played by John Noble. In the movie, Denethor appears completely irrational; he sends his remaining son on a suicidal mission to enemy-captured Osgiliath and refuses to light the warning beacons of Gondor to call for the aid of Rohan. In the book, the danger of his madness is that it seems to follow a certain logic; Sauron does have vastly superior forces, all of which he has surely shown to the Steward. His actions, however, do not immediately proclaim his insanity; the Osgiliath mission is less obviously suicidal, as the city has not yet been overrun, and the warning beacons have indeed been lit, although Denethor expects little help.
For Denethor, leader of the Nandor see: Denethor (First Age).
