It was the inevitable event we all knew would happen—for all men are mortal—but which somehow we could not imagine would actually take place. The death of the sovereign after a reign of seventy years is the end of an epoch but also a personal event, not just for the Royal Family but for the citizens of each realm in which Elizabeth II was Queen. Every member of my parents’ generation in New York can remember where they were when they learned that John F. Kennedy had been assassinated. For my generation, it was the attack on the World Trade…