Gandalf was one of the Istari, known as Gandalf the Grey, and was the second most powerful of the Order. Gandalf played a major role in the winning of the War of the Ring and the Downfall of the Lord of the Rings. He worked long and hard for over 2000 years to end Sauron's reign in Middle-earth, until in 3019 the job was completed by hobbits.
Gandalf first arrived in Middle-earth in about 1000 of the Third Age. Gandalf from this point had many important errands in Middle-earth. He was originally in 2063 sent to find out who the Lord of Dol Guldur was. He failed until 2850 when he entered Dol Guldur and found it under the rule of Sauron. Here he found Thráin and recovered from him the key of Erebor and then escaped. In 2941 he met up with Thorin II and they both decided to go to Erebor to recover the Arkenstone and kill Smaug. He persuaded Thorin to hire Bilbo for an unknown cause, and this became very important in the future, for upon this quest Bilbo came across the One Ring, which he "won" from Gollum. Gandalf always had a suspicion that Bilbo's ring was the One, and from circa 2980 forward he had the Shire watched closely by the Rangers.
In 3001 Gandalf told Bilbo to leave the Ring to Frodo, an act which showed his utter confidence in Shire-folk. Later he started the Quest of Orodruin sending Frodo to Rivendell with the One Ring. He played an important role at the Council of Elrond, for he knew the entire history of the Ring, which he had learned from Gollum. The next year when the Company set out from Rivendell he went with them as the leader of the party until his fall in Moria. He then persued the Balrog to the peak of Zirak-Zigil and cast down the Balrog before dying. He was sent back to Middle-earth, however, in the form of Gandalf the White. After this he broke the spell that Wormtongue had put over Théoden, cast down Saruman, and made critical decisions for Gondor and Rohan. In the Battle of the Pelennor fields Gandalf held back the Lord of the Ringwraiths after the city gates had been broken for a few utterly important minutes until the arrival of the Rohirrim.
Gandalf had the appearance of a worn and bent old man. He had a long, snow-whtie beard and a blue pointy hat, as well as long, bushy eyebrows. He had grey hair and cloaks until after his demise, after which he wore white. As Gandalf the Grey he could die from mortal wound, and did, but upon his return as Gandalf the White he was invincible to all earthly weapons.
By Tim Kirk.