Saruman

Saruman the white is the chief of the Wizards, with great knowledge and power. He dwells at Isengard.

Being skilled in sorcery and wise in the ways of engines, he is the greatest of the council of the Wizards. But he long studied the ways of Sauron, and especially the lore of Rings of Power. He grew proud and desired power for himself. He was granted the Tower of Orthanc at Isengard by the stewards of Gondor where he found a palantir, which he used to view far areas of Middle-earth until he saw the Red Eye and thus he fell under the influence of Sauron.

Corrupted, he made Isengard a place of evil and built red forges and engines of war, and gathered Orcs and Dunlendings, the enemies of Rohan. He also bred the Half-Orcs. His badge bears a white hand and renounced his white cloak and declares himself as Saruman of the Many Colours.