Saruman the white used to be head of the wizarding order until he was turned to Sauron`s side. It started when Gandalf the gray found the one ring at bag end, and rode to isingard to tell Saruman. Saruman already knew however, and had already informed Sauron by using his palantir, which is a round rock like a seeing ball. Saruman and Sauron can talk to one another with this, and they both have one for this purpose. Saruman had informed Sauron of the ring being found, which is why the Nazgul started searching for Frodo(this is unconfirmed). After Gandalf learns of his betrayal the two fight in a wizards duel. Saruman wins the duel and sends Gandalf to the top of the tower of orthanc, were he stays prisoner for a time. After this Saurman starts working with orcs to help bring down the world of men. He starts creating a new breed of orc, called uruk-hai which he uses to hunt down the fellowship and kill Boromir with. It is believed that the whole purpose of this attack was to gain the ring for himself, with it he would become more powerful than Sauron.