Charles III will end his seven-decade wait to be crowned king on Saturday, in a gilded spectacle celebrating the monarchy’s medieval roots and attempting to position it to survive the current era of technological and social change. Charles, who legally became king after Queen Elizabeth II’s death in September, is due to formally receive St. Edward’s Crown during a religion-infused ceremony in Westminster Abbey. The event is expected to put enduring British soft power on display as some 2,000 dignitaries, spiritual leaders and celebrities watch on, with thousands gathering on London’s streets and millions more tuning in from around the...