JAMES MURDOCH declined to speak on the record for this article. He put forward numerous people who know him well to speak on his behalf, and he asked others, including longtime friends from his childhood in New York City and time at Harvard, not to speak. (One of his best college friends, after first agreeing to speak, e-mailed with the note: “Sorry for not getting back to you earlier. As you probably figured out, the P.R. people at News Corp are handling this.”) Many others spoke without first seeking James’s permission.

Through nearly two dozen interviews, on and off the record, with people who have worked directly with him or are close to him personally, a portrait emerges. It suggests an aggressive, ambitious executive who has cemented his stellar reputation in the pay-television business in Asia and Europe, who at times has made assertive plays for expanding his power base within the company, who has nurtured a brand of conservative politics that often puts him at odds with the profit center that is Fox News, and who has shown an eagerness to play in the corridors of power in ways noisier than his father’s more subtle maneuverings.

“There’s an intensity to him,” said Frank Luntz, the Republican pollster, who has worked for James. “The guy’s got intensity wrapped around energy.”

That James works from a standing desk in his office in London  sitting is less efficient in getting work done  adds to the image of him as a tightly wound executive, as do his black belt in karate and his hobby of competitive cycling. So does the way he offers his business card to visitors: with a two-handed thrust, as they do in Asia, where he once ran the company’s regional television business out of Hong Kong. And so does the episode, well told in the British press, of him showing up last April at the office of The Independent, a rival paper, to berate its editor for running advertisements critical of the Murdoch empire’s supposed influence in British elections.

Another business acquaintance, Saad Mohseni, an Afghan media mogul who has worked with James in establishing Farsi1, a joint venture to beam satellite television into Iran, said: “He expresses himself. He swears if he needs to; he gets aggro.”

During 2009 and into 2010  a period that saw the exit of Rupert Murdoch’s longtime deputy, Peter Chernin  the perception within the New York headquarters of the News Corporation was that James was being overly aggressive in positioning himself to be his father’s successor.

That sense was amplified by James’s close relationship with Prince Walid bin Talal of Saudi Arabia, the company’s second-largest shareholder after the Murdoch family. The two men met almost nine years ago, aboard the prince’s yacht in Cannes, France. The relationship blossomed during meetings in London and the Middle East and culminated last year with a Murdoch investment in the prince’s media company, Rotana, and an interview with Charlie Rose in which the prince said James should succeed his father.