A former surgeon, Dr. Stephen Strange was an arrogant and concieted man. But when his hands were damaged in a car accident, he was unable to find any treatment. In desperation, he turned to an old legend he heard, about a healer called the Ancient One living in Tibet. To his surprise, the Ancient One existed. After learning to use magic to foil an attempt to assassinate the old sorceror by his own student, Baron Mordo, the Ancient One accepted Dr. Strange as his successor to become Sorcerer Supreme of Earth.
One of the most powerful magic-users in the Marvel Universe, Dr. Strange has saved the world from mystic threats such as Dormammu and Shuma-Gorath. However, due to being forced to use dark magic to stop the Hulk who was attacking the world, Dr. Strange was replaced by Brother Voodoo as Sorcerer Supreme. Nevertheless, Strange remains a powerful mystic hero. (He is still Sorcerer Supreme in Ultimate MvC3 canon, according to his victory quote)