Winston Churchill, when prime minister, called television a "tuppenny ha'penny Punch and Judy show". He never gave an interview, claiming that television had no part in the coverage of politics.
Surprisingly, his view was shared at Alexandra Palace, where television news started. There was no political editor, but E R (Teddy) Thompson was "parliamentary correspondent": the BBC hierarchy thought the word "political" was itself too political, and it wanted to be above politics.
How things have changed. These days, the Prime Minister and leading politicians are all over the bulletins, and BBC Millbank is a huge processing plant for political news. But the past 50 years have been a painful learning process for both Number 10 and the television broadcasters.
"Coming into a television studio is like entering a 20th-century torture chamber," said Harold Macmillan, Conserv-ative prime minister from 1957 to 1963, "but we old dogs have to learn new tricks."
Before Macmillan, no one had heard of a prime ministerial "image". He was the first to try to project one - with the help of prototype spin doctors. He had become prime minister with trousers that disgraced his tailor, an unkempt moustache and teeth in disarray.
Some 18 months later, as his official biographer put it, "a new self-confident Macmillan appeared on the screen, the disorderly moustache had been rigorously pruned, the smile is no longer apologetic and toothy and he is wearing a spruce new suit". He was the first incumbent of Number 10 to emerge as a TV personality.
But he was also the first prime minister to discover the fragility of a television image. His famed Edwardian unflappability came to appear fuddy-duddy and out of touch. And the opposition leader made the most of it - presenting himself on the news as everything the failing prime minister was not. Labour's Harold Wilson sought to project himself as dynamic and purposeful, having studied videotapes of John F Kennedy.
Wilson becamethe complete professional. One TV newsman told me: "If a cameraman asked Harold to walk down the garden steps from the Cabinet room, across the lawn and stop on a certain leaf facing in a certain direction, he would do it without any sense of condescension - and get it right first time."
But by 1976, after Wilson been party leader for 13 years - nearly eight of them as PM - he'd grown tired in the job and the viewers had grown tired of him. It's what television schedulers call "the wear-out factor". What is wanted is something new and different. And the woman who was to become the longest-serving prime minister of the century was to offer that in spades.
Yet when Margaret Thatcher first became Tory leader, she reacted awkwardly towards television. But she took advice from Gordon Reece, a former producer. "Gordon was terrific. He said my hair and my clothes had to be changed and we would have to do something about my voice," Mrs T said later.
Reece introduced the photo opportunity into British elections. Until 1979 no aspirant to the office of prime minister had given a news conference clutching a two-day-old calf in a meadow. Mrs Thatcher told me at the time: "The cameramen said they did n't want a picture of me with a load of bullocks in superb condition. There was this beautiful calf. The media have their job to do and I am very conscious of that." During her decade in Downing Street she had many clashes with television people, myself among them. A cartoon from those days shows the BBC newsroom with Mrs Thatcher in the newsreader's chair.
As Prime Minster, Tony Blair - along with Alastair Campbell and Peter Mandelson - took the use of television to a new plane. When we gained access to Downing Street to make the documentary News from Number 10, I doorstepped the Prime Minister inside his own official home. Tony Blair had come into his press secretary's office to talk to Campbell without realising we were filming there.
I asked the PM what he thought of TV news. He said that the biggest problem from his point of view was to try and get a developed argument across to the public, "because I am lucky if I get a 30-second clip on the evening bulletins".
So, I asked, was that why he and Campbell were said to spend their whole time trying to spin the news? "It's just modern government now," Blair replied. "There's a 24-hour news media. If a story comes out that says something you have to have the capacity to get on top of it and say: 'Look, sorry, the facts are x and y'. But what matters most to me is to do the things that are really important for the country - otherwise there is no point in doing the job. And people can believe that or not, as they like, but that's what I spend my time thinking about."
It was an impressive peroration, the effect of which was somewhat lessened by Alastair Campbell adding, on camera: "And that's why you have spent the past seven minutes talking to Michael Cockerell." It was, I learnt later, the moment that the spin doctor wished he had bitten his tongue.
The writer makes documentaries for BBC News and is the author of 'Live from Number 10 - the inside story of Prime Ministers and TV'