Before it was unceremoniously killed off for reasons that Julian Fellowes insists have nothing to do with its name becoming synonymous with religious hatred and mass murder, the late Isis was the most-beloved dog in all of Downton Abbey. (Besides Thomas — rawwr.) But how did it get its name? As Hugh Bonneville tells Time, it was all his idea. As the actor recalls, the Granthams’ first dog, Pharaoh, had to be replaced after it didn’t get along with the hounds of the Carnarvons, who owned the estate where the show was shot. The original plan was to pull a Bobby Draper and just pretend the new dog was the same as the old one, but Bonneville wasn’t having it: “I said, ‘Well we can’t just call it Pharaoh. There’s a big difference between this dog and the last one. This one is a bitch and the last one was a [male] dog. And I think people will notice that and it’s half the size.’ And so at that point we said, ‘Well, what should we call it then?’ And I said, ‘Keep it something Egyptian.’ And I just thought of Isis.” And there was an added benefit to the switch: While Pharaoh was “morose,” Isis the dog was “really good fun” — basically, the exact opposite of that other ISIS.