Saruman, aka Saruman the White, was a buddie of Gandalf until he turned evil for no particular reason. He was once a 'wise and powerful wizard' but when he turned against the good guys he decided to burn a load of forests which made Treebeard angry. Treebeard launched a massive attack on Isengard, where Saruman lived, and annihilated his army. Gandalf arrived soon later, only for Saruman to take a tumble off the Tower of Orthanc and die when he hit the bottom. Ouch.
He was later posthumously convicted of Minion Abuse when Wormtongue, groupee for the Sarumen, piped up that he was assaulted by Saruman during his service at Isengard. From that logic, everyone in Rohan filed an abuse claim too as their entire city was assaulted by Saruman.
His buddy Sauron got a bit upset at this point, as he rather liked Saruman. Maybe he just thought their names were too similar. Speaking of similar, a trio of Saruman look-alikes formed a band called the Sarumen after the death of the real Saruman, and went on to be a bit hit in Middle Earth.