Woman rescues man in a cage; he speaks a different language she understands

I have been looking for the title of a historical romance I read years ago. Woman whose father studies an old language (it might be Nordic origin) rescues a man trapped in a cage and being exhibited like an animal. Once rescued, the man ends up protecting the woman from harm.

Hmm. Roughly how long was 'years ago'? Twenty years?

On another site, a user suggested Heart of Honor by Kat Martin.

Thank you! That's it! :)