Aragorn (March 1, III 2934 - March 1, IV 120) was the son of Arathorn, and at a young age he was brought by his mother to Rivendell. He was raised there secretly under the name "Estel" to hide him from the forces of darkness. At the age of twenty, Elrond revealed to him his lineage (that he was the heir of Numenor and great Kings), and following this Aragorn spent nearly seventy years in the wild, traveling Middle-Earth, becoming the greatest hunter-tracker and in disguise serving under Thengel of Rohan and Eccthelion of Gondor, fighting against Sauron. He eventually met and became good friends with Gandalf.
While young, Aragorn fell in love with Elrond's daughter Arwen, and desired to marry her. Elrond forbade it, he would only give his consent if Aragorn fulfilled his destiny and became the King of Gondor and Arnor as well as defeated Sauron. Later on, Aragorn joined the Fellowship of the Ring, vowing to guide Frodo Baggins into the black land of Mordor to destroy the One Ring.
After the apparant death of Gandalf in the mines of Moria, Aragorn took command of the Fellowship, coming into his own as leader but the Fellowship broke at Amon Hen after Boromir was killed and Frodo and Samwise Gamgee went off to Mordor alone.
During the War of the Ring Aragorn aided King Theoden in defense of Helm's Deep against the forces of Isengard, and was present at the breaking of Saruman's staff. He then journeyed into the Paths of the Dead to take control of the ships belonging to the Corsairs of Umbar, and attack the armies of Mordor from the river, claiming victory at the Battle of Pelennor Fields.
It was in Minas Tirith that Aragorn proved himself to be the heir to the throne when he healed the sick and wounded, and then rallied the armies of Gondor and Rohan together and with Gandalf led them to the Black Gate of Mordor for the sole purpose of tricking Sauron into diverting his gaze away from his lands and sending his troops to the Gate allowing Frodo to make it to Mount Doom to destroy the Ring. It was at the Black Gate that Aragorn parleyed with the Mouth of Sauron refusing to give in to despair, and stood ready to face his death in battle with the greater forces of Mordor. But Frodo succeeded and Mordor fell.
Aragorn was crowned King of Gondor and Arnor, taking up residence in Minas Tirith and marrying Arwen. He was given the name Elessar by Galadriel, and restored peace to Middle-Earth. During his one-hundred-twenty year reign, he extended the borders and made Gondor strong again. He and Arwen had one son named Eldarion and several daughters. Eventually he passed away, Eldarion becoming king.