Gandalf first mentions Gollum in �The Shadow of the Past�, when he reveals to Frodo that the ring in his possession (left to him by Bilbo), is in fact the One Ring of Sauron. Gandalf believes that Gollum � the only other being that knew Bilbo possessed the Ring � had been in contact with the Dark Lord, and revealed the names of �Baggins� and �Shire�.
Gandalf also states that he believes that fate may have played some part in Bilbo�s pity for Gollum � that Gollum has some part to play (which turns out to be all too true � see The Return of the King).
Gollum�s sad history is also revealed in this chapter: a hobbit-like creature (a stoor) that lived on the Gladden Fields near the Great River. Known originally as Sm�agol, he killed his friend D�agol to gain the Ring, which D�agol had found on the bottom of the river. Shunned by his family and people, he fled to the darkness of the Misty Mountains to escape the spying Sun and Moon, and discovery mysteries, taking the Ring with him. There, they both remained for 500 years (give or take).
After being released from Mordor, Gollum wanders the wild, before being found by Aragorn, who takes the poor wretch to Gandalf (this is how Gandalf discovers what Gollum has told Sauron). Gandalf entrusts Gollum to the captivity of Thranduil and the Elves of Mirkwood. But Gollum escapes � a fact which Legolas confesses during the council of Elrond. It is believed that during this time, being pursued by both the servants of Sauron and the Elves, he finds refuge in Moria, but cannot escape through the western door.
Thus, he is waiting for the Fellowship when they enter the mines. He tracks their steps from then on � through Moria, to Lothl�rien (where Frodo spots him attempting to climb one of the trees that the Fellowship are resting in), and along Anduin (floating on a log). The breaking of the Fellowship is probably a great aid to Gollum, as it separates the Ringbearer from all his protectors bar one.
