Page "Gandalf" Paragraph 32

In Rivendell, Gandalf helped Elrond drive off the Nazgûl pursuing Frodo and played a great part in the following council as the only person who knew the full history of the Ring.

He also revealed that Saruman had betrayed them and was in league with Sauron.

When it was decided that the Ring had to be destroyed, Gandalf volunteered to accompany Frodo — now the Ring-bearer — in his quest.

He also persuaded Elrond to let Frodo's cousins Merry and Pippin join the Fellowship.