He is a 1,200-year-old who has battled some of the most evil villains, travelling through time and space, and who has saved the world more times than he can remember. He has also captivated television audiences all over the world, an icon to countless fans of all ages from all over world, and has sent millions of children running for cover behind the sofa. But who is he? Who is Who? He is the Doctor, often referred to as Doctor Who.

Doctor Who is a Time Lord from Gallifrey, a planet within a constellation known as Kasterborous. “The Doctor is a legend woven throughout history,” Clive Finch, a character from the show, explains. “When disaster comes, he’s there. He brings a storm in his wake and he has only one constant companion … death.”

This year marks the 50th anniversary of this popular science-fiction TV show created by the BBC, and to celebrate, the network is broadcasting a special episode.

“It all started out as a mild curiosity in the junkyard,” the first ever Doctor had said, “and now it’s turned out to be quite a great spirit of adventure.”

The show was originally planned to be an educational programme led by an alien who travelled to different time periods in his Tardis, a spaceship that changes its appearance to blend in with its surroundings. This idea was scrapped and, because of the low budget, the Tardis stuck to its one appearance – a blue police box that is now iconic – and the show became Doctor Who.

The show got off to a shaky start. The first episode, An Unearthly Child, aired on November 23, 1963 – the day after US President John F. Kennedy was assassinated. Due to a power cut in some areas of Britain, the broadcast was repeated the following week and received mixed reviews. The BBC considered cancelling the programme. But the ratings for the second adventure skyrocketed with the debut of the Daleks, a mutant race encased in an odd metal case on wheels. The Daleks went on to become the Doctor’s greatest enemy and are now as iconic as the Tardis.

Not many television programmes can boast that they’ve run for 50 years with the same protagonist. Well, almost the same. In 1966, the first Doctor, 58-year-old William Hartnell, resigned after an illness caused him to forget and fluff his lines. The show’s writers had to replace him in a way acceptable to the wide fan base the show had garnered.

The solution was to give the Doctor the ability to renew every cell in his body when faced with death, in a process called “regeneration”. So far there have been 11 Doctors, all with new faces and personalities.

The most popular Doctors to date have been the fourth, Tom Baker (1974-1981), who played the role the longest; the 10th, David Tennant (2005-2010) who boosted the popularity of the show after its relaunch; and the current, 11th Doctor, Matt Smith (2010-2013) who stepped into the role when the show found great popularity in America, and who will regenerate this Christmas.

You can’t save the world without making enemies, and the Doctor is no exception. Since 1963, he has battled countless villains – some scary, some not-so-scary and some downright comical. Looking back, the most memorable villains include the power-mad Daleks, who despite looking like big pepper pots have proved so popular even the producers dare not kill them off; the Weeping Angels, who switch between stone statues and pointy-toothed demons in the blink of an eye; the silver-coated Cybermen; the smart-suited Silence who have the ability to make you forget them as soon as you look away; and the Doctor’s arch-enemy and fellow Time Lord, The Master. Less popular villains who are unlikely to be back for a rematch are the fat green Abzorbaloff, the not-so-sweet Candyman and the Sensorites, who were scared of the dark.

For the 50th anniversary special, The Day of the Doctor, we will see our heroic Time Lord up against the metamorphic Zygons.

Patrick Troughton (left), the second Doctor, with companion Jamie McCrimmon (Frazer Hines)

Everybody needs friends – even the centuries-old Doctor. During his 50 years on the air, he has shared the Tardis with more than 50 travelling Companions. Mostly they have been female and from modern Earth, but he has also travelled with men, with a futuristic space pilot, a primitive tribal woman, and a robotic dog.

Most Companions turn out to have a good influence on the Doctor and help the audience to understand what’s going on by asking the Doctor questions viewers themselves would ask. All fans have their favourite Companions, but some of the most memorable include journalist Sarah Jane Smith, who was Companion to four doctors and went on to have her own spin-off show The Sarah Jane Adventures; Scottish Highlander Jamie McCrimmon; Time Lady Romana; Rose Tyler; Donna Noble; and Amy Pond. The Doctor’s current companion, Clara Oswald is his most mysterious yet, having already died twice in different time periods.

Doctor Who fans, who call themselves Whovians, tend to divide the show into two parts: Classic Who (1963 to 1989) and New Who (2005 to present).

The Classic era featured eight regenerations of the Doctor. It reached its peak with the fourth Doctor, played by Tom Baker, when 9 to 10 million viewers were tuning in every week. But audiences began to slip away after Baker left, with fans moaning about a decline in writing standards. Things improved with the arrival of Sylvester McCoy as the seventh Doctor, but it never regained the ratings of its heyday. To the dismay of fans, the series was cancelled in 1989, but hopes were raised for a reboot with the 1996 feature film, Doctor Who: The Movie. Unfortunately, although Paul McGann made a credible Doctor, it failed to ignite a buzz for the Doctor and it appeared he was lost in time.

From left: Rory Williams (Arthur Darvill), the 11th Doctor (Matt Smith) and Amy Pond (Karen Gillan)

The year 2005 marked the rebirth of Doctor Who with a new exciting writer, Russell T Davies, and a younger cast: Christopher Eccleston played the ninth Doctor and former teen star Billie Piper was his Companion, Rose. With slick plots, villains old and new, and simmering chemistry between the Doctor and Rose, the show was an immediate success and was watched by almost 11 million viewers worldwide.

In December 2005, David Tennant continued to reel in new fans when he stepped into the Doctor’s time-worn shoes as the 10th Doctor. His popularity, especially with the younger generation, meant fans were devastated when both Tennant and Davies announced they were to leave the show in 2010.

Many doubted they could be replaced, but those doubts were proved wrong when Smith, the youngest-ever Doctor, burst onto the screen with new companion Amy Pond, and the new writer Steven Moffat has been credited with producing some of the most complex and enthralling Doctor Who story lines ever.

Earlier this year, news leaked that Smith will be leaving the show this coming Christmas. Who would be the next Doctor? Many speculated that after all these years, the Doctor might undergo a gender change and regenerate as a woman, but in August, the BBC announced in a 30-minute live show that the 12th Doctor will be veteran actor, Peter Capaldi.

At 55, Capaldi will be the oldest Doctor since Hartnell. The role is a dream come true for Capaldi, who has been a Doctor Who fan since he was a schoolboy who reportedly bombarded the Doctor Who Magazine team with letters. It is speculated he will portray a darker Doctor, especially when compared to his predecessor who was arguably the most comical and childish Doctor to date. As with everything Whovian, time will tell.

Watch the premiere of Doctor Who: 50th Anniversary Special - The Day of the Doctor on November 24, at 3.50am on BBC Entertainment (NowTV #529/ CableTV #130). The show will be repeated on November 24 at 7.30pm on the same channel.

Watch the premiere of Doctor Who Explained on November 23 at 9pm on BBC Entertainment.

YP cadet Isabel Lai met two of the actors who have played the Time Lord and learned lots about the TV show. Read her interview HERE