Filled with wanderlust and a renewed curiosity towards exploring time and space, the Fourth Doctor left all ties of his previous incarnation's exile behind on Earth, setting off to travel the Cosmos. This incarnation of the Doctor initially travelled with Sarah Jane Smith and Harry Sullivan, but Harry chose to remain on Earth when the opportunity arose. The Doctor and Sarah continued on their adventures until the Doctor was summoned to Gallifrey, necessitating that he leave Sarah Jane behind as humans were not allowed on Gallifrey.

After tangling with the Master on Gallifrey, he met and travelled with Leelaof the Sevateem. During his travels with Leela, the Doctor gained a new companion in the robot dog, K9. Returning once more to Gallifrey to stop an invasion of Vardans, Leela and the original K9 stayed behind there.

On the White Guardian's orders, the Doctor began looking for the Key to Time with fellow Time Lady Romana and K9 Mark II. Once that search was concluded, the Doctor and Romana went on the run from the Black Guardian. Not long after, Romana regenerated into a new body and continued to travel with the Doctor and K9. When they attempted to answer a Gallifreyan summons, the trio accidentally passed into the smaller universe of E-Space.

During his travels in E-Space, the Doctor gained a new companion in the teenaged mathematical genius Adric. Romana and K9 stayed behind in E-Space as the Doctor and Adric departed for N-Space. There, they encountered a Trakenite princess named Nyssa and a human named Tegan. The foursome successfully prevented the destruction of the universe by the Master, but only at the cost of this incarnation's life.

The Doctor prepared for the worst when the Watcher, an entity born of his own immediate future, appeared to warn him of his demise. Due to the Master messing with the rotation controls for the Pharos radio telescope, the Doctor fell a great height. Suffering terrible injuries, he was assisted by the Watcher in his last moment, who joined with him and helped him regenerate into his next incarnation.

Appearance  Edit

Clothing Edit

Personality  Edit

Habits and quirks Edit

Biography Edit

A day to come Edit

Post-regeneration Edit

Early adventures Edit

The Nerva Beacon Edit

Returning to UNIT Edit

Walking in eternity Edit

Return to Gallifrey Edit

Companionless  Edit

Captured by the Master Edit

Skirmish on Aprilia III Edit

Old friends Edit

Milena and Ms. Young Edit

New acquaintances Edit

Travelling with a savage Edit

Adopting K9 Edit

Lord President of Gallifrey Edit

After the Presidency Edit

Nest Cottage Edit

A return to wandering Edit

Seeking the serpent's egg Edit

Travels with K9 Edit

Quest for the Key to Time Edit

Further adventures with Romana Edit

The new Romana Edit

Shada  Edit

After Shada Edit

Lone adventures with K9 Edit

K9 and Sharon Edit

More adventures with K9 Edit

Final voyages with Romana Edit

Trapped in E-Space Edit

Return to N-Space Edit

Final adventures Edit

Stalked by the Watcher Edit

Death  Edit

Post-mortem Edit

Undated adventures Edit

Alternate timelines Edit