Gandalf

Gandalf the Grey is a Maiar, a servant of the Valar (who are like the gods of Middle Earth.) He and several others of the Maiar were sent to Middle Earth to help the people there. He was given one of the rings of the Elves, Nayra, the ring of fire. His sword is Glamdring, which he acquired on the journey to the Lonely Mountain with Bilbo and 13 dwarfs. He also has a staff, which is his symbol as a wizard, and it holds his magical powers.

Soon after his journey with Bilbo, he started to study about the one Ring. Years later, when he had great knowledge of the Ring, he found that Bilbo had found it in Gollum's cave, and Bilbo had now given it to Frodo. After this, he told Frodo to go to Rivendell with the Ring, while he went to see the head of the order of wizards, Saruman. There he learned of Saruman's betrayal, and he was held prisoner at Isengard, where he still might be if it wasn't for the King of Eagles that carried him from the tower.

The Eagle took him to Rohan, where he tamed the lord of all horses, Shadowfax. He then went to Rivendell, where the Fellowship of the Ring was established and he was given the task of guiding them to Mordor. This journey took him into the mines of Moria.

Although he is a wizard, he did die in "The Fellowship of the Ring" in the mines of Moria. He fought a Balrog of Morgoth, in which both he and the Balrog perished. Yet since his sacrifice was for the friends of his fellowship, he was brought back, and given even more powers than before, and took Saruman's place as the head of the wizards.

After this he went to Rohan, and freed King Theoden from the enchantment of Saruman. And then rode to find Eomer and his men, to aid King Theoden at the Battle of Helms Deep. After this he rode to Gondor with Pippin, where he fought at the Battle of Gondor. This battle was won with the aid of the Riders of Rohan and Aragorn and the Dunadan. After this he fought at the Black Gate of Mordor with soldiers of Rohan  and Gondor to give Frodo his chance of destroying the Ring. After the Ring was destroyed he left Middle Earth with the Elves to the land of the Valar, for his task was complete.