His inspiration for the Daleks, whose mechanised bodies appear to glide across the ground, came from watching the Georgian State dance troupe on television. The female dancers, with their long voluminous skirts, seemed to have no legs as they smoothly criss-crossed the stage. The Daleks were an instant success with the viewing audience and returned to threaten the good doctor in series after series, as well as on the big screen. They also gave rise to a spectacular range of merchandising spin-offs that made their creator a wealthy man. One spin-off that brought no royalties but pleased him enormously was the inclusion of the word "Dalek" in the Oxford English Dictionary.
Born in Cardiff, Nation began his professional career as a stand-up comedian, but, though audiences liked his jokes, they didn't much care for the way he told them, so he became a scriptwriter instead. In 1955, in his mid- twenties, he moved to London and joined Associated London Scripts, whose stable of writers included Spike Milligan, Johnny Speight, Ray Simpson and Alan Galton - Tony Hancock's writing team. Terry Nation was to write some 200 radio comedy scripts for the likes of Harry Worth, Eric Sykes and Frankie Howerd, before moving to television.
When Tony Hancock dropped Galton and Simpson, Nation was one of the writers to whom he turned. Their collaboration was a friendly if sometimes frantic one, but did little to reverse the slide in Hancock's fortunes. It was round about this time, in 1963, that Nation was invited to write some episodes for a new television series, Dr Who, the brainchild of Sydney Newman, head of BBC television drama. His initial inclination was to turn down the offer, being firmly of the view that the programme was destined for the scrapheap. Changing his mind and taking the job, he said later, was the shrewdest move he ever made.
He now all but abandoned comedy for popular television drama. Throughout the Sixties he wrote for one successful Lew Grade series after another - The Saint, The Baron, The Avengers, The Persuaders - rising through the ranks to become script editor and associate producer on the later programmes. The hallmark of a Terry Nation screenplay was a crisp, imaginative plot, laced with sharp, witty dialogue. However intense the drama, humour was seldom far away, and always used to good effect.
By the early Seventies he felt able to branch out on projects of his own. With Clive Exton he wrote and produced a feature film, The House in Nightmare Park (1973), starring Frankie Howerd and Ray Milland (a former pupil at Nation's school in Cardiff), a comedy thriller which unashamedly tipped its hat at the 1939 Bob Hope classic The Cat and the Canary. For television he created the series Survivors, the story of a group of people who survive a killer virus which wipes out most of the world's population. This was followed by Blake's Seven, the inter-galactic adventures of a band of outcasts. Like Dr Who, the latter developed a cult following.
The project that gave him the most pleasure, however, was his children's book Rebecca's World (1975), a wonderfully imaginative adventure story named after his daughter. A best-seller in the UK, the book was also published in several other countries, including the United States.
In 1979, Terry Nation fulfilled a long-time ambition to work in Hollywood, settling there with his wife Kate and their children, Rebecca and Joel. In the years that followed he worked for Columbia, 20th Century Fox and MGM, developing programme ideas and script doctoring, but never managed to repeat the success he had enjoyed in Britain. His final few years were dogged by ill-health in the form of emphysema.
Nation had an attractive quality of self-deprecating humour and liked nothing better than to reduce his family and friends to helpless laughter, preferably over a drink or two.
Terry Nation, writer: born Cardiff 8 August 1930; married 1968 Kate Gaunt (one son, one daughter); died Los Angeles 9 March 1997.