Shazar

Shazar was a half-Time Lord who left Gallifrey to pursue power. He had been a friend of the Doctor's when they both lived on Gallifrey. Shazar aided the Daleks in their quest to control time and defeat the Time Lords. He was stopped by the Fourth Doctor with the help of the High Council. As a punishment, Shazar was shrunk back into a glass bottom and was left on a primitive planet where he could do no harm. (COMIC: Return of the Daleks)