Shadowheart (Medieval Hearts, #2)

Dangerous and dashing assassin Allegreto wants to regain his rightful place in the rich Italian principality of Monteverde. Happily, the means to do so is Lady Elena, long-lost Monteverde princess and sole heir to the kingdom. Though she is promised to his rival, Allegreto seizes her ship, takes Elena prisoner, and weds her, thus beginning their battle of wits and passion.