PW's original list is here - from their annual Facts & Figures coverage - and all I'm doing is summarizing and commenting on the historical novels on it. I'd recommend visiting the original article by Daisy Maryles for the comprehensive stats as well as info on changing trends.
Earlier this year, PW asked publishers to submit sales figures on titles that sold more than 100,000 copies during 2010. Only print sales of new books counted -- those shipped and billed. Returns were supposedly taken into account.
Among the top 15 hardcover fiction bestsellers we have:
#3 - Kathryn Stockett, The Help (1,317,397 copies)
#12 - Ken Follett, Fall of Giants (621,562 copies)
It's notable that The Help was #3 on last year's chart as well, with 1,104,617 copies sold in '09. I still own a copy and still haven't read it! Blame the publishers/authors/editors/bloggers who keep urging new books on me. The rest of the top 15 is dominated by Stieg Larsson, a predictable crop of thrillers (Grisham, Patricia Cornwell, James Patterson and his coauthors), plus Nicholas Sparks, a couple of mysteries, and Franzen's Freedom.
Others that sold more than 100,000 copies, in descending order of sales:
Seth Grahame-Smith, Abraham Lincoln: Vampire Hunter (ok, I'm not sure if this really counts as a historical novel, but with eye-opening sales of 230K+, it's worth mentioning)
Danielle Steel, Legacy
Karl Marlantes, Matterhorn: A Novel of the Vietnam War
Francine Rivers, Her Mother's Hope
Philippa Gregory, The Red Queen
Francine Rivers, Her Daughter's Dream (sequel to Her Mother's Hope)
Elizabeth Kostova, The Swan Thieves
Francine Rivers, Redeeming Love (reprint of a classic)
David Mitchell, The Thousand Autumns of Jacob de Zoet
Catherine Coulter, The Valcourt Heiress
Newt Gingrich and William R. Fortschen, Valley Forge
Sarah Blake, The Postmistress
...And that's it. This isn't to say that there aren't other definitions of "bestseller" we could use, but when you look at sales of this magnitude, this is what we have. The two debut novels on the list are the Stockett and Marlantes. With the exception of the Sarah Blake, the remainder are subsequent novels by authors whose previous books were bestsellers. I've read Fall of Giants, Red Queen, and Thousand Autumns and enjoyed all three, especially the first and last. Which ones have you read?
On the trade paperback side, heavy hitters were the reliable sales of Robert Goolrick's A Reliable Wife (658,000 copies!); Jeannette Walls' Half-Broke Horses; Kate Morton's The Forgotten Garden; Sara Gruen's perennial favorite Water for Elephants; the Guernsey Literary & Potato Peel Pie book; more Philippa Gregory, Lisa See, and Francine Rivers; and Leila Meacham's Roses. Also, for the first time, PW has put together a list of e-book bestsellers, and some historicals did quite well.