 It was actually... The Romans? No, it was 19th century social history. And that was kind of the foundation of my interest in demography. Do you think about it once a day? Oh, at least 15 times a day. But I do actually think that if Catherine of Aragon had had a couple of sons, Henry VIII probably would have had a few affairs. And I wonder if we'd be all that interested in the Tudors. It's a lot to do with the six wives. And the extraordinary fact, actually, that for six wives, Henry VIII didn't have a single grandchild.