Few private citizens have ever been more central to the state of world affairs than the man lying in that hospital bed, awaiting his children’s arrival. As the head of a sprawling global media empire, he commanded multiple television networks, a global news service, a major publishing house and a Hollywood movie studio. His newspapers and television networks had been instrumental in amplifying the nativist revolt that was reshaping governments not just in the United States but also across the planet. His 24-hour news-and-opinion network, the Fox News Channel, had by then fused with President Trump and his base of hard-core supporters, giving Murdoch an unparalleled degree of influence over the world’s most powerful democracy. In Britain, his London-based tabloid, The Sun, had recently led the historic Brexit crusade to drive the country out of the European Union — and, in the chaos that ensued, helped deliver Theresa May to 10 Downing Street. In Australia, where Murdoch’s power is most undiluted, his outlets had led an effort to repeal the country’s carbon tax — a first for any nation — and pushed out a series of prime ministers whose agenda didn’t comport with his own. And he was in the midst of the biggest deal of his life: Only a few weeks before his fall on Lachlan’s yacht, he shook hands on a London rooftop with Robert A. Iger, the chief executive of the Walt Disney Company, consummating a preliminary agreement to sell his TV and film studio, 21st Century Fox, to Disney for $52.4 billion. But control of this sprawling empire was suddenly up in the air.