The White Tower of Ecthelion was the tall tower in the Citadel of Minas Tirith, on top of which was the Gondorian banner that went one thousand feet into the air.
The White Tower had graced the highest point of Minas Tirith since ancient times. The Tower of Ecthelion was used to bear the plain white standard of the Stewards of Gondor of the City, which flew from its pinnacle, and—at least during the last years of the Third Age. It is 50 fathoms (300 feet) tall. The Tower stood in the center of the Citadel on the seventh level of the city. In front of the Tower was the Place of the Fountain where the White Tree of Gondor grew.
In the Tower Hall was the throne of the King of Gondor upon a dais, and at the foot the dais on the lowest step was a black chair where the Steward of Gondor would sit. There was a chamber high in the Tower and above it in the summit there was a secret room where the Palantir of Minas Anor, called the Anor-stone, was kept.
King Calimehtar first built the White Tower in TA 1900 in order to house the palantír. In TA 2698, the Tower was repaired and rebuilt by the Steward Ecthelion I, some three centuries before the War of the Ring, and for whom the Tower came to be named.
The elite military unit in Minas Tirith was called the Guard of the Citadel or the Guard of the Tower. At the time of the War of the Ring, Boromir and Faramir - the sons of the Steward of Gondor - each bore the title Captain of the White Tower. Boromir, the Steward's heir, was also the High Warden of the White Tower.
Then Pippin cried aloud, for the Tower of Ecthelion, standing high within the topmost wall, shone out against the sky, glimmering like a spike of pearl and silver, tall and fair and shapely, and its pinnacle glittered as if it were wrought of crystals; and white banners broke and fluttered from the battlements in the morning breeze, and high and far he heard a clear ringing as of silver trumpets.
-The Return of the King: chapter 1,"Minas Tirith"
Pippin met Denethor II, the Steward of Gondor, in the Tower Hall. Denethor's son Faramir came to the Tower Hall the next day, and Pippin and Gandalf learned of his encounter with Frodo and Sam in Ithilien. When Faramir was brought back to the city gravely wounded on March 13, Denethor retreated to his chamber high in the Tower with his son and would not come down. In the secret chamber of the Tower, Denethor looked into the Palantír and saw images manipulated by Sauron that caused him to despair.
After the War of the Ring on May 1, the standard of the Stewards of Gondor was raised for the last time. That day Aragorn was crowned King and when he entered the Citadel; the standard of the Kings of Gondor bearing the White Tree and the Stars was unfurled on the pinnacle of the Tower of Ecthelion.
It was renamed the Tower of Ecthelion after the Steward Ecthelion I who rebuilt it. Also called the Tower of Denethor during the reign of Denethor II.
- The Return of the King
- Lord of the Rings: Appendix B "The Tale of Years," pgs. 367, 369
- The History of Middle-earth, vol. XII, The Peoples of Middle-earth: "The Heirs of Elendil," pg. 200