But Mr. Murdoch carried on, determined to challenge his public image, one that a former editor of The Times of London, Harold Evans, who was summarily fired by Mr. Murdoch, has described as the embodiment of “charismatic authority,” a leader who derives compelling authority from popular perception rather than by his direct orders. But Mr. Murdoch was having none of it. His objective, he said, “was always to tell the truth, certainly to interest the public, to get their attention, but always to tell the truth.”

Another theme that ran through the day’s testimony was, as Mr. Murdoch put it, to “put to bed once and for all the myth” of his having “used the influence of The Sun, or the supposed political power, to get favorable treatment.” Rather, he said, it was the politicians who had sought his favor, seeking him out in the hope that he would use his papers to improve their electoral chances. He implied that as often as not, it was a take-it-or-leave it proposition for him. “Some impress me more than others,” he said. “And I could tell you one or two who particularly impressed me.”

One who gained Mr. Murdoch’s seal of approval was Mrs. Thatcher, who had Mr. Murdoch for lunch at the prime minister’s country residence, Chequers, just as both were consolidating their power in 1981. Setting a pattern that he said had stood through all of his subsequent encounters with Britain’s leaders, he treated it as a social occasion, a chance to get to know somebody who was making a mark. “I have never asked a prime minister for anything,” he said. “I did not expect any help from her. Nor did I ask for any.”

Two prime ministers who seem to have fallen short in Mr. Murdoch’s reckoning were Mr. Brown, whose relatively brief tenure at Downing Street was doomed when Mr. Murdoch switched The Sun’s backing to Mr. Cameron’s Conservatives from the Labour Party of Mr. Brown before the 2010 election. With apparent relish, Mr. Murdoch told of taking a telephone call from Mr. Brown in which the prime minister, a Scot with a notoriously short temper, and in Mr. Murdoch’s telling, “not in a balanced state of mind,” told him, “Well, your company has declared war on my government, and we have no alternative but to make war on your company.”

Mr. Murdoch continued, “And I said, ‘Sorry about that Gordon, thank you for calling, end of subject.’ ” Mr. Brown told the BBC that Mr. Murdoch’s account of their exchange was “wholly wrong.”

Mr. Cameron, too, appeared to have fallen short, though whether that might have had something to do with the government’s push for rigorous inquiries — and police investigations — into the tabloid scandals was not an issue broached in his testimony. Mr. Murdoch, seemingly keen to telegraph a languid disinterest, said he had forgotten about a visit that Mr. Cameron paid to him on the island of Santorini, off the Greek coast, when Mr. Cameron was still an opposition leader in the summer of 2008.