Gandalf is a protagonist in J. R. R. Tolkien's novels The Hobbit and The Lord of the Rings. He is a wizard, one of the Istari order, and the leader of the Company of the Ring.
As a wizard and the bearer of one of the Three Rings, Gandalf has great power, but works mostly by encouraging and persuading.
He sets out as Gandalf the Grey, possessing great knowledge and travelling continually. Gandalf is focused on the mission to counter the Dark Lord Sauron by destroying the One Ring.
He is associated with fire; his ring of power is Narya, the Ring of Fire. As such, he delights in fireworks to entertain the hobbits of the Shire, while in great need he uses fire as a weapon.
As one of the Maiar, he is an immortal spirit from Valinor, but his physical body can be killed.
In The Hobbit, Gandalf assists the 13 dwarves and the hobbit Bilbo Baggins with their quest to retake the Lonely Mountain from Smaug the dragon, but leaves them to urge the White Council to expel Sauron from his fortress of Dol Guldur. In the course of the quest, Bilbo finds a magical ring.
The expulsion succeeds, but in The Lord of the Rings, Gandalf reveals that Sauron's retreat was only a feint, as he soon reappeared in Mordor. Gandalf further explains that, after years of investigation, he is sure that Bilbo's ring is the One Ring that Sauron needs to dominate the whole of Middle-earth.
The Council of Elrond creates the Fellowship of the Ring, with Gandalf as its leader, to defeat Sauron by destroying the Ring. He takes them south through the Misty Mountains, but is killed fighting a Balrog, an evil spirit-being, in the underground realm of Moria. After he dies, he is sent back to Middle-earth to complete his mission as Gandalf the White.
He reappears to three of the Fellowship and helps to counter the enemy in Rohan, then in Gondor, and finally at the Black Gate of Mordor, in each case largely by offering guidance.
When victory is complete, he crowns Aragorn as King before leaving Middle-earth for ever to return to Valinor.
