It was only a matter of time before Bjorn Ironside -- played by Alexander Ludwig of The Hunger Games -- found himself a love interest on Vikings. And this love interest is a slave girl, Porunn, played by French actress Gaia Weiss in her breakout role. But this begs the question: who was Porunn, and how common were slaves in Viking society?

Gaia gave an interview to TV Fanatic right before her debut on the show late last week: unlike many of the other characters on the show, Porunn isn't someone based on historical fact, and she certainly wasn't Bjorn's wife in the original Norse sagas. She, in fact, is a character that's completely created for the series. Still, Gaia said that she is really enjoying her Vikings experience thus far, and her co-stars have been welcoming and gracious towards her.

"When you look around you, it is a village. It's not green-screen or blue-screen, everything around you is just the Viking world. It makes it a lot easier to act and really believe in what you're doing," she said. "I was extremely glad to hear that Michael Hirst is present on set to guide the cast and crew. This show is his baby, after all, and no one knows these characters quite like Michael does. When I arrived I had many questions about my character and he [Michael Hirst] was always there to answer."

Porunn, like Athelstan (played by British stage actor George Blagden), is a slave in Viking society... a society which, by first glance, seems pretty progressive, and unlikely to have slaves. So... were they common in Viking society?

Well, according to Viking Answer Lady (a sort of Viking guru), there were a class of people known as the "thrall," or "unfree people" in Viking society. Many of the thrall became slaves as a result of warfare or raids (the latter being the case in Athelstan's plight, though Ragnar (Travis Fimmel) clearly treated him better than a typical Viking would treat a slave, and eventually grew to consider him a friend). Was it common? Not as much as one might think. Was it unusual? Again, no: thralls were a part of Viking society, however unpleasant that part may be.