A new decade - the 1970s - saw a new Doctor Who as Jon Pertwee took over from Patrick Troughton to become the third incarnation of the Doctor. The TV series itself underwent some significant changes as the new era began. The programme was now in colour, and for budgetary reasons the Doctor was exiled on Earth, rather than roaming through time and space as had previously been the case. UNIT (United Nations Intelligence Taskforce) had proved very popular with the viewers when the organisation helped Patrick Troughton's Doctor against the Yeti and the Cybermen. The Brigadier, Captain Yates and Sergeant Benton became semi-regular characters, helping the Doctor during his exile on Earth. In his role as scientific advisor to UNIT, the Doctor had the assistance of firstly Liz Shaw, then Jo Grant and finally the journalist Sarah Jane Smith. These characters, along with the Master, became the known as the Doctor Who family, the phrase that the actors used to describe themselves.

Jon Pertwee's Doctor

John Devon Roland Pertwee was born on 7 July, 1919 into a famous theatrical family. He was a rebellious child, and indeed a rebellious adult, who was expelled from his prep school for impersonating Tarzan in the school toilets and causing considerable damage to the cisterns. He was also expelled from RADA (Royal Academy of Dramatic Arts) and told he had no future as an actor. This was rather disproved when Noel Coward came to see the last play that he was involved in. When asked if he had seen any good performances he mentioned just two, both played by Jon Pertwee. As with most actors he had a grounding in stage acting, but his amazing ability for mimicry and voices saw him earning a good living on radio.

During WWII he served in the Royal Navy. His first commission involved shore training that led to his transfer from HMS Hood three days before it was sunk with all hands, apart from three survivors. When he met the survivors on This Is Your Life in 1975, he burst into tears as the tragedy that had always haunted him was revisited.

When he accepted the role of Doctor Who, he was most famous for his role in the radio comedy The Navy Lark. He was also familiar to the public for his three scene-stealing turns in Carry On Cleo, Carry On Screaming and Carry On Cowboy. It was his Navy Lark co-star Tenniel Evans who suggested that he contact the BBC about Doctor Who. He was initially reluctant to run the risk of typecasting. He asked the producers how to play Doctor Who and was told to play it as himself. His famous reply was 'Who the Hell's that?'

To everyone's surprise he decided to play Doctor Who as a dramatic part. It was a decision that paid huge dividends. His Doctor has often been described as a James Bond-type figure. Although his Doctor had a love for gadgets, this is an essentially inaccurate reading. The role called for a mixture of action, intelligence, philosophy and compassion. The last two qualities were completely missing from 007, and it was those qualities that defined Pertwee's Doctor. He was often critical of the Army mentality exhibited by Brigadier Lethbridge Stewart, and in an early episode registered his disgust at UNIT's decision to blow up the Silurians.

It was not only the army that felt the sharpness of the Doctor's tongue. Civil Servants were often berated for following rules rather than common sense. On these occasions the Doctor could be pompous and irrational. The third Doctor preferred to reason with aliens, trusting in their innate goodness until proven wrong. On more than a few occasions this approach worked, but when force was required he proved adept at Venusian Aikido. He was apparently one of the few two-armed beings to master this skill. As an actor Jon Pertwee was not a great fan of the 'techno-babble' that was often required. This was significantly reduced at his request, although the phrase 'reverse the polarity of the neutron flow' became a fan favourite. When he used the line in the stage play The Ultimate Adventure he received a standing ovation.

In dress this Doctor was flamboyant and striking. His cape billowed out as he ran to his emergencies. His velvet jacket was the height of elegance, particularly when offset by a tasteful frilled shirt! At well over 6 feet tall Jon Pertwee towered over most of his fellow actors and this gave him even more presence and power in his portrayal of the Doctor.

The Doctor Who Family

Brigadier Alistair Gordon Lethbridge-Stewart (Nicholas Courtney)

The head of UNIT operations in the UK, Brigadier Lethbridge-Stewart was a military man through and through, with all the strengths and weaknesses that that entailed. He was a stickler for the rules and this brought him into conflict with the Doctor on many occasions. The Doctor regarded him as unimaginative whilst he regarded the Doctor as an unnecessary risk taker. Despite this, the two men had the greatest respect for each other. Their verbal sparring was a delight and despite his unimaginative demeanour, the Brigadier was not always on the losing side. When the Doctor's third incarnation ended and the regeneration started the Brigadier simply said, 'Oh well! Here we go again!'

Sergeant John Benton (John Levene)

Sergeant Benton was the Brigadier's enforcer. He would take orders without questioning and carry them out without hesitation. In every way he was the perfect soldier, but being outranked by both the Brigadier and the Doctor he could be left in difficult positions on occasion. He would sometimes stand there listening to the two giving and countermanding orders until one had the upper hand. Once that happened the order was executed. When Jo Grant joined UNIT there was an implied attraction between the two, but in true military fashion Benton was nothing less than the perfect gentleman. His bravery was never in question, but even he was a little disconcerted by his first trip in the TARDIS, an experience he refused to repeat.

Captain Mike Yates (Richard Franklin)

The easygoing and suave Captain Yates was every inch the public school educated Army officer. He was popular with his men and impressive under fire in most cases. He flirted with Jo Grant and made it clear that he had more to offer than the solid Sergeant Benton. However, he started to lose his lustre during The Green Death when he was hypnotised by the computer BOSS. This weakened his resilience and he tried to betray his colleagues when a group of environmentalists attempted to roll back history to a 'Golden Age'. Brigadier Lethbridge-Stewart gave his protégé the opportunity to resign from UNIT to save him from a court martial. In the final story of the Pertwee era, Planet of the Spiders, he redeeemed himself to some extent by helping UNIT against the cult that called up the spiders from Metebelis 3.

Liz Shaw (Caroline John)

The extremely intelligent and resourceful scientific advisor became the Third Doctor's assistant at the beginning of his exile on Earth. Her ability to almost match the Doctor in intelligence changed the dynamic of the programme. Unfortunately she was years ahead of her time and the character was packed off to Cambridge University to do research. In recent years her reputation has grown amongst fans of the series, but her replacement would be the best remembered assistant of the era.

Jo Grant (Katy Manning)

The dizzy and gorgeous Jo Grant was a cultural icon in the early 70s. In contrast to the extremely intelligent and well qualified Liz Shaw, Jo Grant owed her position as assistant to the Doctor to a well placed relative. However she was resourceful and not adverse to using her feminine charms to escape from trouble. Even the normally immune Doctor melted in her presence and looked after her like a father. He was guilty of that most human of emotions, jealousy, when she fell for Professor Jones. The Doctor's reaction to her decision to leave was that of a broken hearted man. When she tells him that Professor Jones reminds her of a younger version of the Doctor he replies ruefully, 'I don't know whether to be flattered or insulted!'

His lonely drive away from the farewell party at the end of The Green Death was one of the most touching moments of the whole series. After her departure Katy Manning did a fondly-remembered photo shoot with a Dalek for a men's magazine, covered in nothing more than a sink plunger!

Sarah Jane Smith (Elisabeth Sladen)

At the beginning of Jon Pertwee's final season a replacement for Jo Grant was needed. Sarah Jane Smith was really the Fourth Doctor's assistant even though she started with Pertwee. On- and off-screen, the relationship between Doctor and assistant was never as close as the one that Pertwee and Manning had shared. With her more defiant approach and self-reliance, she was an assistant for a new era.

The Master (Roger Delgado)

The Master, a renegade Time Lord like the Doctor, proved to be the Doctor's nemesis during his exile on Earth. Although the exact relationship was never made clear, the two Time Lords knew each other on their home planet of Gallifrey. A number of fans of the series have speculated that they were once best friends, a valid reading given the various comments passed between the two. At the end of Colony in Space the Master asks the Doctor to rule the universe with him. The Doctor replies: 'I want to explore the universe, not rule it', a comment that neatly encapsulated the difference between the two.

There was talk of a final battle between the two in Pertwee's final season, but that was tragically ended by Roger Delgado's death in a car crash soon after his final appearance in Frontier in Space. Pertwee himself never recovered from the double blow of Manning's departure and Delgado's death, and the Third Doctor's era really ended with The Green Death.

Classic Third Doctor adventures

Every long-running series contains episodes or stories that encapsulate everything that makes the programme successful and popular. As every era of Doctor Who is different, the most fondly remembered programmes tend to be those that show the strengths of the particular lead actor. Whilst many fans enjoy The Sea Devils and Day of the Daleks, for anyone new to the programme the following three stories should serve as a good introduction to the Jon Pertwee era.

Spearhead from Space

This was Jon Pertwee's first adventure and arguably the best first story of any Doctor. When the TARDIS arrives on Earth, at the start of his exile, the Doctor is still extremely disorientated by his forced regeneration. His arrival coincides with an apparent shower of meteorites. They are in fact parts of a hive mind called the Nestene Consciousness. He is taken to hospital and found to have two hearts. The news reaches the Brigadier who rushes to the ward expecting to find the Doctor. He doesn't recognise the man in the bed and takes a while to be convinced that only his face has changed. The Doctor has to recover quickly to deal with almost indestructible plastic dummies called the Autons who are controlled by the Nestene Consciousness. In one of the series' most chilling moments, shop dummies break out of the windows and go on a murderous rampage. It set the tone for the whole era and gave Pertwee's Doctor a great start.

The Daemons

This was Jon Pertwee's favourite story and a fan favourite over thirty years later. Professor Horner is an archaeologist digging in Devil's End looking for a Viking burial site. A local white witch called Miss Hawthorne tells him to stop as he will unleash powerful forces. The local vicar Mr Magister is in fact the Master and he is using black magic rituals to summon Azal, a Daemon that humans have used as the model for the Devil in art and literature. The Doctor rushes to Devil's End and finds himself in a battle with dark forces that threaten to destroy the whole planet. This story shows off the ensemble playing of the 'Doctor Who family' with every member taking an important role. The Doctor is dependent upon the skills of all his friends as he battles for survival. It was a controversial programme in its day with the depictions of black magic. There were even suggestions that the Master was using authentic ritual chants. In fact the terrifying chant spoken by the Master is 'Mary had a little lamb' said backwards! In one of his best lines the Brigadier deals with the appearance of an animated gargoyle by turning to one of his soldiers and barking out the order: 'Chap with the wings there! Five rounds rapid!' It is a terrific story that thrills viewers every time it is shown.

The Green Death

In South Wales some very unsettling events are taking place. Miners are returning from work with a luminous green rash that ends up killing them. It is caused by chemical waste from the local factory. Environmentalists in a local commune called 'The Wholeweal Community', but known by locals as 'The Nuthutch', try to warn the community about the danger in its midst, but are largely ignored. The Doctor and Jo travel to Wales to investigate and find one of the series' most iconic monsters in the form of giant maggots. It is a race against time as the Doctor, with the help of Professor Jones, tries to discover an antidote to the green death. Feelings are confused as Jo falls in love with Professor Jones and the Doctor realises that he might lose her. This programme has the pace of a thriller and the advantage of an environmental plot line that was years ahead of its time, but is still relevant today. The battle between the Doctor and BOSS the super-computer is superbly played out as the two minds battle for supremacy. Its main weakness is the portrayal of South Wales which trots out every cliché in the book. Maybe Pertwee had this programme in mind when he appeared in an episode of The Goodies as mad Welsh vicar Revd Llewellyn Llewellyn Llewellyn Llewellyn two years after this programme was made!

After the Pertwee Years

In five seasons, Pertwee took a failing show that was close to cancellation and transformed it into a cultural icon. The programme was in very good health when he handed over to Tom Baker as the fourth Doctor. Following this, Jon Pertwee took the role of another long running character in the title role of Worzel Gummidge. He did, however, return to the role of the Doctor on a number of occasions in later years, appearing alongside Patrick Troughton and Peter Davison in the 20th anniversary special The Five Doctors. In two radio plays, The Paradise of Death and The Ghosts of N-Space, Pertwee demonstrated his prowess in that particular medium with a fantastic performance as the Doctor. On stage he portrayed the Doctor in the successful play, The Ultimate Adventure. As well as this he was a regular attendee at conventions giving his time to his army of adoring fans. Jon Pertwee died on 20 May, 1996.