Saruman
Saruman came to Middle-Earth as the chief of the Istari near the beginning of the Third Age, and made his home in the tower of Orthanc deep in the valley of Isengard.
For centuries, he led the White Council, and he himself was their chief expert in Ringlore. Unlike the other four Istari, Saruman desired power at any cost, and became obsessed with the One Ring. For centuries he desired it, and eventually the Dark Lord Sauron knew he could use Saruman's desire for power to his advantage. Saruman used his palantir to spy on Mordor and discovered that Barad-dur had been rebuilt. However, Sauron was aware of him, and began to manipulate him.
Saruman and Sauron forged a secret alliance, in which Saruman pledged his loyalty to the Dark Lord. Saruman's strategy was two-fold: either gain the One Ring for himself and rule Middle-Earth, or allow Sauron to recover it and be on Sauron's side when Sauron claimed victory. What he did not know was that Sauron was aware of his plans.
Gandalf journeyed to Isengard seeking Saruman's council, and revealed to Saruman that the Ring was in the Shire. Saruman tried to persuade Gandalf to join him and eventually rule. Gandalf refused, and was soon imprisoned by Saruman atop Orthanc. Saruman then began to turn Isengard into a war camp, breeding elite Uruk-Hai, and destroying the trees of Isengard. He also undermined the neighboring kingdom of Rohan by sending his servant Grima Wormtongue to King Theoden's court to persuade him not to take any action against Isengard. He also sent his Uruk-Hai after the Fellowship of the Ring to capture the hobbits and bring him the One Ring.
They succeeded in capturing Merry and Pippen, but they escaped and helped rally the Ents against Isengard. The Ents attacked and occupied Isengard, trapping Saruman in Orthanc. Gandalf the White soon arrived, leading the armies of Rohan, and confronted Saruman, offering him a chance to repent. Saruman refused, so Gandalf banished him from the Council and broke his staff, stripping him of power. In a fit of rage, Grima threw Saruman's Palantir out a window where it was claimed by Aragorn.
After the defeat of Sauron, the Ents released Saruman, and he and Grima journeyed to the Shire, where agents he had there allowed him to take over. He was known among the hobbits there as "Sharkey" (derived from an orcish word meaning 'Old Man'). The four hobbits returned and managed to drive Saruman out. But after lashing out at Grima, the servant (after years of abuse and torture) attacked Saruman and cut his throat. Saruman's spirit rose from his body and looked towards Valinor, but was rejected and his spirit scattered on the wind.
