When he joined what was to become the Daily Mail in 1968, much of Fleet Street thought he was mad. He was then foreign editor of the Daily Express, the ruling title of the British middle classes which sold 3.5 million copies a day, and he was already being tipped as a future editor.
Instead, he joined the Daily Sketch because of his friendship with its owner Lord Rothermere. Fleet Street's predictions looked to be confirmed when the newspaper closed two years later. However, Sir David, at 40, was made editor of the Daily Mail, Rothermere's flagship.
He immediately turned it into a tabloid and dragged it further to the right of the political spectrum. He developed longer news features, waspish female columnists and whole sections aimed at women. According to the Fleet Street doggerel, the Mail was known as the paper read by "the wives of the people who run the country".
Yesterday, Lord Rothermere said: "I knew David English as a journalist and close friend for over 30 years. He took over the editorship of the Daily Mail at the lowest ebb in its fortunes and carried out with genius its conversion to a middle-market tabloid so that, by the time he retired, the Daily Mail had again achieved the dominant position it had under Lord Northcliffe."
The second most important relationship of Sir David's reign was with Baroness Thatcher, whom the Mail supported in her battle for the Tory party leadership and she shared much with him. They were both middle- class Methodists.
In 1982, he was knighted by Lady Thatcher and his paper targeted what remained of the British left-wing with delight and ease. Targets such as gays, socialist Labour councils and the National Union of Mineworkers made easy hunting.
But the Mail's success was based on more than simply a feeling for the politics of the time. Sir David laid claim to creating a "cult of the editor" and created a highly professional news organisation that he described as being run by "creative tension". Others described it as a rule of fear. Executives have been known to emerge in tears from meetings and his legendary tongue-lashings were felt all the way down the chain of command.
But the paper was meticulously edited and an army of journalists battled to squeeze their copy into the paper.
Sir David retired from day-to-day running of the newspaper in 1992 to become chairman and chief executive of Associated Newspapers, looking after its television interests, and last year became chairman of ITN.
Sir David also began to play a growing role in the industry's move to self-regulation in the face of criticism of the tactics of some tabloid newspapers. He was a member of the Press Complaints Commission and chairman of the Editors Code of Practice Committee.
Associated is expected to move quickly to fill his position at the top of the group, but Lord Rothermere's quandary must be that the obvious candidate, the Mail's editor Paul Dacre, has continued the paper's formidable sales success.