Mistress trilogy (Mary Balogh)

In this captivating novel, Mary Balogh, the premier writer of Regency romance, invites you into a world of scandal and seduction, of glittering high society and intrigue, as an arrogant duke does the unthinkable—he falls in love with his mistress.
 
She races onto the green, desperate to stop a duel. In the melée, Jocelyn Dudley, Duke of Tresham, is shot. To his astonishment, Tresham finds himself hiring the servant

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When Edward Ailsbury, the new Earl of Heyward, rescues Angeline Dudley from public embarrassment, Angeline falls instantly in love. But the stuffy Earl has little concern for Angeline. Edward wishes only to wed an old friend for an amicable companionship, a good match for his staid persona. But Angelina may show Edward that comfort is no match for passion.