The Murdochs are in many ways the most important media story of the last 50 years. On three continents their shoddy journalism, blind political ambition, outright racism and unlimited greed have done more damage to democracy than the actions of all their rivals put together. The family’s internal competitions and political alliances are the subjects of dozens of books and documentaries, as well as the inspiration for Succession, the HBO hit now filming its fourth season. The Australian journalist Paddy Manning’s new book focuses on Lachlan Murdoch, the family’s current leader who will be fully in charge if his 91-year...