Gandalf

Gandalf the Grey also known as Mithrandir is the wisest of the Wizards. He rarely used magic openly.

Biography
Gandalf travels much and knows many peoples and places like the Ents, the Eagles, the lords of Gondor and Rohan. The Elves gave him the Ring of Fire, one of the Rings of Power.

In the Third Age he crept into the vast chambers of Dol Guldur and discovered that Sauron had returned.

He met with Thorin Oakenshield seeking ways to  destroy Smaug. As the Dwarves were not  stealthy creatures, and  they needed stealth  to  succeed against a dragon he hired Bilbo Baggins as a scout and burglar. During their adventures he found his magic sword, Glamdring.

He assisted Bilbo leave the Shire and move to Rivendell. We was worried to see that Bilbo was very reluctand to leave the magic ring to Frodo Baggins. He traveled and researched and found that it was the One Ring created by Sauron. He returned to the Shire and warned Frodo that Sauron knew that his Ring was in the hands of a Baggins.

They decided that on Frodo's birthday they had to go to Rivendell and there decide their next movement. He adviced him that he should use a fake name, and that he should travel with trustful friends. However Gandalf didn't manage to make it, and Frodo had to leave alone.