The Third Doctor (Jon Pertwee)

The Third Doctor, played by Jon Pertwee, was exiled by the Time Lords on Earth for a significant period of his life. The technological limits of the time period, and the constraints of his exile, often made him frustrated and bitter. However, he retained his endearing compassion toward his human companions.

This Doctor worked for UNIT as their unpaid scientific adviser, and remained in their service after his exile was ended. Unlike his earlier incarnations, he was quite willing to engage others physically, and cut a more dashing figure.

His foremost enemy was a fellow Time Lord, the Master. Although appalled by the disregard for life inherent in the Master’s schemes, the Doctor treated their relationship as somewhat of a friendly rivalry, even enjoying their battle of wits. The Master reflected an equally casual attitude back at him. He also held out hope that he could rehabilitate the Master, whom he had once considered a friend. Though the Master sometimes teamed up with the Doctor to deal with foes who threatened them, he always bent to dark and malicious desires, which kept their mutual antagonism alive.

In the field, the Doctor was aided by Sergeant John Benton, Captain Mike Yates and Brigadier Alistair Gordon Lethbridge-Stewart. The Doctor often took exception to the Brigadier’s military approach, just as the Brigadier was frequently irritated by the Doctor’s air of superiority and seeming disregard for authority. Despite this, the two men ultimately developed an easy mutual trust and strong friendship.

He was initially assisted in the laboratory by Dr. Elizabeth Shaw. A capable scientist in her own right, she eventualy left to pursue her own work, and the Doctor was given a new assistant, Jo Grant. She was bubblier and had less scientific training, but the Doctor found her a most useful companion in his adventures during and after his exile. They developed a great fondness for each other. Jo left UNIT to marry scientist Clifford Jones.

Shortly thereafter, the Doctor was joined by inquisitive newswoman Sarah Jane Smith. Her journalistic skills and curiosity proved both useful and occasionally hazardous in their travels together.

The Third Doctor regenerated after being exposed to large amounts of radiation during his efforts to stop the Eight Legs of Metebelis III.