Gandalf is one of the most important characters in Middle Earth and played a huge part in the War of the Ring.
He has a huge influence on the events of both The Hobbit and The Lord of the Rings. He is a constant source of wisdom and advice to many of the characters, guiding them in the fight against Sauron. He wasn't afraid to tell anyone the truth, not even kings, and he was instrumental in bringing together Middle Earth in defiance against Sauron.
If it wasn't for Gandalf, the Ring might have remained safe in The Shire until the Ringwraiths came to claim it; he realised it was more than just an amusing trinket and saw what it really was. He managed to convince Bilbo to part with it, setting the stage for the journey to Mordor and the Ring's eventual destruction.
After he fell fighting the Balrog, he was reincarnated as Gandalf the White, returning to Middle Earth even more powerful to see his task through to the end, not resting until Sauron was defeated.
See how much you know about the wise wizard with this quiz!