The Husband Gamble by Jude Knight

The abducted bride; the upright earl. The only place they match is over the chess board.

Lady Osbourne’s famed matchmaking skills may not be enough to find a match for Miss Amaryllis Fernhill, who was abducted right out of the church in front of her groom and has been no one knows where for six years.
Nathan Belvoir, Earl of Hythe, wants a countess that will live up to his illustrious name and embellish his diplomatic and political career. Miss Fernhill is obviously unsuitable. Why, then, can he not look away?

(This book is part of The Wedding Wager multi-author series)