Lachlan Murdoch’s path to succession has been rocky at times, but he is finally getting the family prize: sole possession of the keys to his father’s media empire.

Mr. Murdoch, the elder son of Rupert Murdoch, solidified his rise to the top on Thursday when his father, 92, announced that he would retire from the boards of Fox Corporation and News Corporation. They are among the most influential media businesses in the world, with publications and news channels in Europe and the United States that have pushed politics on both continents decidedly to the right for more than three decades.

The move leaves Lachlan Murdoch, 52, as the executive in charge of all day-to-day operations at the companies, whose holdings include Fox broadcasting, Fox News and The Wall Street Journal.

The younger Mr. Murdoch is less overtly political than his father; some confidants say he is more interested in negotiating a potential merger than he is in talking to a president or a senator. But as the heir apparent for the past few years, Mr. Murdoch has made significant efforts to prove he is committed to the future of the businesses and aligned with his conservative father politically, and is certain to continue Fox News’s right-wing stance.

He has defended Fox News’s programming and was the chief executive of its parent company as it continually broadcast conspiracy theories and falsehoods pushed by President Donald J. Trump and his allies about the 2020 presidential election. His views have on occasion been further to the right than his father’s, claimed a former News Corp Australia editor, Chris Mitchell, in a recent memoir.

Rupert Murdoch indicated in a note to employees on Thursday that he expected his son to continue the conservative editorial stance that Fox News is known for.

“The battle for the freedom of speech and, ultimately, the freedom of thought has never been more intense,” he wrote. “My father firmly believed in freedom, and Lachlan is absolutely committed to the cause.”

Perhaps one of the biggest differences between Lachlan Murdoch and his father is his location. Since 2021, he has lived in Sydney, Australia, nearly 10,000 miles from the companies’ New York headquarters. His commutes to the United States on the corporate jet have already proved tiring for him, a person inside News Corp said, and he often has to take phone calls in the middle of the night because of the time difference.

Lachlan and Rupert Murdoch, through a company spokesman, declined to be interviewed for this article.

Lachlan Murdoch, the third of his father’s six children, was born in London and raised mostly in New York, attending private schools and boarding schools. After he graduated from Princeton, where he studied philosophy, he decamped to Australia and, like his father, spent time in the family’s newspaper business.

In his 20s, he rose through the ranks to run News Corp’s Australia business, happily proclaiming that he loved the Australian way of life and that it was where he felt “most myself,” according to a profile in New York magazine. He also pushed the company to make a pivotal investment in a small online real estate business, REA Group, a stake now worth billions of dollars.

That period, though, was also marked by a couple of early business failures, including One.Tel, a telecommunications venture with his friend James Packer, an Australian billionaire, that collapsed in 2001.

In 2000, Mr. Murdoch was made deputy chief operating officer of News Corp and moved with his new wife, the British Australian model Sarah Murdoch, to New York. But when it became clear to him that his father was siding with Roger E. Ailes, the chief executive of Fox News, he left the company and even the country.

The attention over who would take over the company turned to his younger brother, James, who was running British Sky Broadcasting, which was part-owned by the Murdochs.

Lachlan Murdoch returned to Australia with his family and spent the next decade outside the News Corp bubble. He founded a private investment company, Illyria, buying stakes in media businesses including a network of Australian radio stations.

By 2014, Mr. Murdoch had been persuaded by his father to return to the family business, moving to Los Angeles. He became a nonexecutive co-chairman of News Corp and 21st Century Fox, in a move that signaled he was back in the mix. After his father sold the bulk of his empire, including 21st Century Fox, to Disney for nearly $72 billion in 2019, Mr. Murdoch was named chief executive of the new Fox Corporation, the parent company of Fox News, cementing his place in Rupert Murdoch’s succession plan.

His brother, who frequently donated to liberal causes, had become increasingly concerned about Fox News’s politics and sought to cut all ties from the businesses. In 2020, James Murdoch resigned from the board of News Corp with a letter noting “disagreements over certain editorial content published by the company’s news outlets and certain other strategic decisions.”

Lachlan Murdoch’s tenure atop Fox Corp has been rocky. Fox News’s persistent broadcasting of conspiracy theories about vote-rigging in the 2020 election earned it numerous defamation lawsuits. In April, Fox settled with Dominion Voting Systems for $787.5 million, a case that generated an avalanche of negative publicity for Fox and resulted in the ouster of one of its most popular hosts, Tucker Carlson. The company still faces shareholder lawsuits and another blockbuster defamation case.

Mr. Murdoch will soon lose his trusted lieutenant Viet Dinh, a close friend who served as Fox’s chief legal officer and presided over the Dominion suit. Mr. Dinh’s departure was announced in August.

And the media business isn’t what it used to be. Television viewers are switching to streaming, upending the economics of the industry, while many of the print publications in Mr. Murdoch’s News Corp portfolio face declining circulation and a tough advertising market.

“Fox Corp — like other TV network groups — is grappling with existential questions about the viability of the cable bundle and the challenges in monetizing streaming assets,” said Paul Verna, principal analyst at Insider Intelligence.

“That said,” he added, “given the strong ideological affinities between Lachlan Murdoch and his father, and given the elder Murdoch’s advisory role as chairman emeritus, I don’t expect a noticeable shift in the company’s editorial positioning or strategic direction.”

Paddy Manning, the author of “The Successor,” a biography of Mr. Murdoch, said he had been “firmly in charge” at Fox Corporation for some time now, and had some proven successes, including the purchase of the successful streaming service Tubi.

“Rupert’s retirement and handover to Lachlan is a clear signal to the rest of his family, the directors and shareholders of both companies, as well as the wider world,” Mr. Manning said, “that Lachlan is the chosen successor and he has complete confidence in his leadership.”