Editing Third Doctor (section)

==Biography==
After the Doctor was found guilty of breaking the Time Lord laws of non-interference and forced to regenerate, he began his third incarnation in exile on 20th century Earth. The Third Doctor immediately formed a working relationship with the British contingent of [[UNIT]], an international organisation tasked to investigate and defend the Earth against extraterrestrial threats.

It was a partnership initially born out of convenience — the Doctor required facilities to try to repair his [[TARDIS]] to break the exile, and UNIT needed his expertise to combat the threats they encountered. There is some disagreement about when the Third Doctor's UNIT stories were set, with some evidence that they were contemporary stories set at the same time they were broadcast (the early 70s), and some evidence that they were set in the near future. According to the production team, there was an intention to set the stories in the near future, but the writers did not always remember this and set the stories in the present.

The Doctor also developed a good working relationship with [[Brigadier Lethbridge-Stewart]], whom he had first encountered, in his previous incarnation, as a Colonel in command of troops fighting [[Yeti (Doctor Who)|Yeti]] and the [[Cyberman|Cybermen]]. As well as the Brigadier, he developed friendships with other regular UNIT colleagues including [[Sergeant Benton]] and Captain [[Mike Yates]]. When meteors were seen falling to Earth in Essex, the Doctor together with a UNIT scientist named [[Liz Shaw]] were to face the [[Auton|Autons]] for the first time. The Autons were to be one of the Doctor's recurring foes. At the conclusion of this adventure, the Doctor became UNIT's scientific advisor. After facing [[Silurian (Doctor Who)|Silurians]], the so-called Ambassadors of Death and the Inferno project, Liz was replaced as the Doctor's assistant by a feisty but slightly scatter-brained young woman named [[Jo Grant]].

After meeting Jo, the Third Doctor encountered his greatest nemesis (next to the Daleks) — [[The Master (Doctor Who)|the Master]]. A renegade Time Lord, the Master plagued the Third Doctor with his diabolical schemes, including the summoning of an ancient Dæmon, and unleashing the terrifyingly powerful Kronos, a Chronovore. The Doctor's exile continued until it was lifted by the Time Lords after he helped save them from destruction at the hands of Omega. The Third Doctor, free to roam space and time again, soon ran into the Master and an even older enemy — [[Dalek|the Daleks]]. Although the Master was a criminal genius, the Doctor was always able to outwit him in all his schemes. Whilst facing the ecological destruction wrought by Global Chemicals and the super computer BOSS, Jo met and fell in love with Dr. Clifford Jones. Marrying Jones and following him to the Amazon on an expedition, Jo left a saddened Doctor.

The fiercely independent investigative journalist [[Sarah Jane Smith]] became the Doctor's new companion after stowing away in his TARDIS. The Third Doctor's final adventures saw them defeating the [[Sontaran|Sontarans]] in medieval England and the Daleks on the planet Exxilon. The Third Doctor contracted radiation poisoning on the planet Metebelis 3, during the events of [[Planet of the Spiders]]. When the TARDIS brought him back to UNIT headquarters, he collapsed, regenerating into the [[Fourth Doctor]].