Here's a great little site I found for popular names during different time periods.
Naming our characters is always a challenge but it is also very important when it comes to historical fiction, imho.
Another tidbit with regard to naming your characters comes from the meaning of the names. I love having fun with those. Also, it's interesting to figure out the back story of how and why your character was given that name by his or her parents. Was it a family name? Was it a combination of two names, reduced, edited to become his or her own unique name. Were there reasons why your character wasn't named after his grandfathers? Was he or she given a name that was never used except when they were in trouble? Explore the possibilities, you'll be surprised just how much you can learn about your character by simply researching his or her names.