1967-1968 Jeremy Childs
The First Doctor was a member of a secret Gallifreyan Anti Terrorist Group called TOD (Temporal Operations Directorate) who battle the Daleks throughout the series. At the same time the Doctor in his human guise of Doctor John Smith is romancing 18th Century gentlewoman Alice Hargreaves (Susan George).
The second series sees the Doctor preparing to renounce his alien heritage and settle with Alice in 18th century London. But the daleks follow the doctor, kill Alice and seriously damage the TARDIS causing it to crash through time and leading to the Doctor's first regeneration...
Although both series were made by Rediffusion, Thames Television broadcasted the second series
1970-1973 Michael MacKenzie
The second doctor and the TARDIS materialise in modern day London where they attract the attention of runaway Kate Preston (Judy Loe). This Doctor is far more cynical and bitter then his predecessor. His growing attachment to Kate helps him heal the scars of his past and he becomes a dashing playboy style character.
This version also seen the introduction of a new enemy. The Hydrax. A liquid based parasitic lifeform who can take human form. The Doctor and Kate (and later Sam Harper played by Pamela Stephenson) battle the Hydrax and various other enemies. The Doctor regenerates saving the Earth from a Hydrax invasion force...
1974-1978 Patrick Stewart
The third and perhaps the most loved Doctor. He is more of an Edwardian swashbuckler. Allying himself with UNIT (who we encounter during the second doctor's reign) and Sam, This doctor focuses mainly on earth based threats. He regenerates foiling a Dalek plot to destroy the Earth's core...
1978-1981 John Nettles
The 4th Doctor is the most alien. His "deaths" while saving the Earth have made him less enamoured of his adopted world. He spends much of his tenure looking through space and time for any remnants of Gallifrey. Sam leaves him early on and he has no companions throughout his time.
He believes he has found his home when he receives a signal from Morbius a timelord exiled on the planet Praxis. But Morbius seeks to destroy the Doctor in revenge for his own exile for attempting to overthrow the High Council.
In the climatic battle, Morbius opens a black hole near Earth to lure the Doctor back. Morbius is sucked in the black hole but the Doctor is seriously injured. As the TARDIS lands on Earth. The doctor regenerates...
1981-1986 Robert Powell
The 5th Doctor harks back to his 3rd self. An adventurer with a strong sense of indignation against injustice. There is no tenure wide enemy. Instead the Doctor along with his companions Harriet Morgan (Angela Bruce) and Nick Callgahan (Mike Berry) encounter foes old and new.
This 5th Doctor regenerates foiling a joint Dalek/Hydrax plan to ignite an anti matter bomb over Earth
1986-1990 Stephen Fry
The 6th Doctor is a true intellectual. Dressed as a modern man but with the style of an regency dandy the 6th Doctor abhors violence and uses reason and intelligence to defeat his enemies.
This is also the most selfless of doctors. He gives his life to save his young companion Lucy Flynn (Patsy Kensit) after she is subjected to a deadly poison administered by Morbius.
1990-1995 Colin Firth
The 7th Doctor is the most cultured. He is a lover of music, literature and art. He perhaps more than his previous selves fights to save the beauty of the universe.
His "humanity" leads to possibly the most heartrending regeneration. He pushes his companion Sally Mills (Daniela Denby Ashe) through a time gate to save her from a Dalek hit squad....
Ae before. When Thames lost their franchise on 1992, Carlton took over the production