He was born on August 8, 1930 in Wales. He was a comedic script writer for "Hancock's Half Hour", a sketch show starring Tony Hancock, which was based on a popular BBC radio show of the same name. He wrote episodes for such shows as The Avengers, and The Saint. In 1963, he wrote the Doctor Who episode The Daleks (aka The Mutants) for the BBC, which introduced the most popular villians on the show, and was responsible for the BBC's first merchandising boom.
He was incorrectly credited to be the creator of the Doctor Who series in the movie versions of the show (Dr. Who and the Daleks and Dalek Invasion Earth 2150 AD). The series was created by committee but BBC Head of Drama Sydney Newman is regarded as being the nearest to a creator, although he has never received the same level of credit for it as he did for the creation of The Avengers.
Along with writing many Doctor Who television shows and movies, Nation has also wrote episodes of Blake's 7 and MacGyver, and the televion series Survivors. He died on March 9, 1997 in Los Angeles, California of emphysema.