@birdsandbats Back in the day they were imported so they certainly could have been. Seeing as the subspecies was mixed with Amur to create more visually appealing animals, though, it's equally as likely that these were hybrids.
@birdsandbats No idea, though as I said there's a decent chance they are true Bengals. I'm not too familiar with the history of the taxa in captivity and have no idea when they started getting crossbred. If you're going as far back as 1879, though, I'd say they're more likely to be pure than not. If memory serves the last purebred Bengal Tiger in England only died in the late 2000s.
