Even though Downton Abbey has seen several major character deaths in its first five seasons — the sixth and final one begins airing in the U.S. on Jan. 3 — it was still shocking to viewers last season when Lord Grantham's beloved dog, Isis, passed away.
It was controversial too: some viewers wondered whether the dog had fallen prey to its unfortunate name, though show creator Julian Fellowes told TIME that the dog's in-show death and the rise of the real-world ISIS were completely unrelated.
Though it's been no secret over the years that Isis' name was inspired by the Egyptian theme set by Season 1 dog Pharaoh, Hugh Bonneville recently shared how he himself came up with the dog's name. Chatting with TIME about the show's final season and real-life 1920s slang, the Lord Grantham actor explained that, though Pharaoh would be forever preserved in the show's opening credits, the dog who played him didn't get along with another set of dogs who took precedence on set:
The Carnarvons who own Highclere Castle, where we filmed some of the show, they have Labradors and they were quite territorial over having a dog [around]. At the beginning of the second season, this assistant director came over and said we’re doing the first scene with the dog and here’s the dog, and I went, 'Right, this isn’t the same dog.' And they said, 'Hmm? They’re ready on set.'
Julian Fellowes happened to be there that day and 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.
Switching to a female dog solved the problem with the Labradors at Highclere, and it solved another problem too: the first dog was, Bonneville said, "the most morose Labrador I've ever met," and added little to his scenes. The dog who played Isis, on the other hand, was "really good fun" — even though the actor said he now regrets having chosen that particular Egyptian name.
"So that’s how Isis was born," he joked, "but it’s still Pharaoh’s ass that my name comes after."