Maiden's Hand by Susan Wiggs

Roguishly handsome Oliver de Lacey has always lived lustily: wine, weapons and women are his bywords. Even salvation from the noose by a shadowy society provides no epiphany to mend his debauched ways.

Mistress Lark's sole passion is her secret work with a group of Protestant dissidents thwarting the queen's executions. She needs no other excitement– until Oliver de Lacey drops through the hangman's door and into her life.

As their fates become inextricably bound together in a struggle against royal persecution, both Oliver and Lark discover a love worth saving even dying for.