Gandalf the wizard was the chief organiser of Thorin Oakenshield's expedition to the lonely mountain. It was Gandalf who first proposed that Bilbo the Hobbit should be taken on as the "Burglar", seeing in Bilbo qualities of character that the poor Hobbit himself was riot even aware of.

Although absent from their adventure at certain times, attending to other important business, he nonetheless accompanied them during most of the critical stages of the journey. By means of ventriloquism he out witted hungry Trolls, He slew the great goblin in the caverns of the misty mountains, and by calling upon his ancient friendship with the great eagles rescued the dwarves from a desperate attack from Wargs. Finally and probably most importantly, he proved a good and just councillor to the squabbling Dwarves, Lakemen and Wood elves during their dispute over the inheritance of Smaug's treasure.